Technical Guidance Reference

Transcription

1 to 4 s Turning Edition... 2 Milling Edition... 7 Endmilling Edition... 2 Drilling Edition SUMIBORO Edition s SI Unit Conversion List Metals Symbols Chart (Excerpt) Steel and on-ferrous Metal Symbol Chart (Excerpt) Hardness Scale Comparison Chart Standard of Tapers Dimensional Tolerance of Standard Fittings Dimensional Tolerance and Fittings... 4 Surface Roughness... 4

2 The Basics of Turning, Turning Edition Calculating Cutting Speed Calculating Power Requirements () Calculating rotation speed from cutting speed f s n =, v c X D m Example: v c =5m/min, D m =mm n =, 5 = 478 (min - ) 3.4 n : Spindle Speed (min - ) v c : Cutting speed (m/min) D m : Inner/outer diameter of workpiece (mm) X : π 3.4 (2) Calculating cutting speed from rotational speed v c = X D m n, Refer to the above table ødm n ap Feed Direction n : Spindle speed (min - ) v c : Cutting speed (m/min) f : Feed rate per revolution (mm/rev) a p : Depth of cut (mm) D m : Diameter of workpiece (mm) P c = v c f a p k c 6 3 V P c H =.75 Rough value of kc P c : Power requirements (kw) v c : Cutting speed (m/min) f : Feed Rate (mm/rev) a p : Depth of cut (mm) k c : Specific cutting force (MPa) H : Required horsepower (HP) V : Machine efficiency (.7 to.85) Aluminum: 8MPa General steel: 2,5 to 3,MPa Cast iron:,5mpa Three cutting force components Relation between cutting speed and cutting force Relation between feed rate and specific cutting force (for carbon steel) F c : Principal force F f : Feed force F p : Back force Calculating cutting force P = k c q, = k c a p f, Fc Fp Ff P : Cutting force (k) k c : Specific cutting force (MPa) q : Chip area (mm 2 ) a p : Depth of Cut (mm) f : Feed Rate (mm/rev) Principal Force (),6 8 Rake Angle: Rake Angle: Cutting Speed (m/min) Relation between rake angle and cutting force Principal Force () 2,8 2,4 2,,6 2 2 Rake angle (degrees) Specific cutting force (MPa) 8, 6, 4, 2, Traverse Rupture Strength 8MPa 6MPa 4MPa Feed Rate f (mm/rev) When feed rate decreases, specific cutting force increases. Machined Surface Roughness Theoretical (geometrical) surface roughness h = f RE h: Theoretical surface roughness (μm) f : Feed rate per revolution (mm/rev) RE: ose radius (mm) RE f h Actual surface roughness Steel: Theoretical surface roughness.5 to 3 Cast iron: Theoretical roughness 3 to 5 Ways to improve surface finish roughness () Use an insert with a larger nose radius (2) Optimise the cutting speed and feed rate so that built-up edges do not occur (3) Select an appropriate insert grade (4) Use wiper insert Relation between nose radius and 3-part force Cutting Force () Principal Force Feed Force Back Force ose Radius (mm) Large nose radius increases back force. Work Material: SCM44 (38HS) Insert: TGA224 Holder: PTGR Cutting Conditions: v c =m/min, a p = 4mm, f =.45mm/rev 2

3 Forms of Tool Failure and Tool Life, Turning Edition Forms of Tool Failure Classification o. ame of Failure Major Causes of Failure (8) () (9) Failure Caused by Mechanical Factors () to (5) (6) (7) Flank Wear Chipping Fracture Wear caused by the scratching effect of hard grains contained in the work material Fine breakages caused by high cutting loads or vibration Large breakage caused by the impact of an excessive mechanical force acting on the cutting edge s (5) (7) () (4) () (6) (3) (2) () Failure Caused by Thermal and Chemical Reactions (8) (9) () () Crater wear Plastic deformation Thermal cracking Built-up edges Cutting chips removing tool material as it flows over its top rake at high temperatures Deformation of cutting edge due to softening at high temperatures Fatigue from rapid, repeated heating and cooling cycles during interrupted cutting Work material is pressure welded on the top face of the cutting edge Tool Wear Curve Forms of Tool Wear Long chips Fracture due to decreased strength Poor surface roughness Face flank wear Crater wear KT Rake Face Wear Burrs occur Side flank wear V Flank Wear Width (VB) (mm) Flank wear Initial wear Steady wear Sudden increase in wear Crater Wear Depth (KT) (mm) Crater wear on rake face V2 Average flank wear VB Cutting Time (T) (min) Cutting Time (T) (min) Edge wear VC Poor dimensional accuracy Burrs occur Flank Wear Higher cutting force Wear increases rapidly right after starting cutting, then moderately and proportionally, and then rapidly again after a certain value Wear increases proportionately to the cutting time Tool Life (V-T) This double logarithm graph shows the relative tool life (T) with the specified wear over a range of cutting speeds (Vc) on the X axis, and the cutting speed along the Y axis Flank Wear Crater wear Tool wear Flank Wear Width mm VB vc vc2 vc3 vc4 T T2 T3 T4 Cutting Time (min) Crater Wear Depth (mm) KT vc vc2 vc3 vc4 T' T'2 T'3 T'4 Cutting Time (min) Tool life Cutting Speed (m/min) Invc Invc2 Invc3 Invc4 InT InT2 InT3 InT4 Lifetime (min) Cutting Speed (m/min) Invc Invc2 Invc3 Invc4 InT' InT'2 InT'3 InT'4 Lifetime (min) 3

4 Cutting Edge Failure and Countermeasures, Turning Edition s Insert Failure and Countermeasures Insert Failure Cause Countermeasures Flank Wear Tool grade lacks wear resistance Cutting speed is too fast Feed rate is far too slow Select a more wear-resistant grade P3 P2 P K2 K K Increase rake angle Decrease cutting speed Increase feed rate Crater Wear Cutting Edge Chipping Tool grade lacks crater wear resistance Rake angle is too small Cutting speed is too fast Feed rate and depth of cut are too large Tool grade lacks toughness Cutting edge breaks off due to chip adhesion Cutting edge is not strong enough Feed rate and depth of cut are too large Select a more crater wear-resistant grade Increase rake angle Change the chipbreaker of the insert Decrease cutting speed Reduce feed rate and depth of cut Select a tougher grade P P2 P3 K K K2 Increase amount of honing on cutting edge Reduce rake angle Reduce feed rate and depth of cut Cutting Edge Fracture Tool grade lacks toughness Cutting edge is not strong enough Holder is not strong enough Feed rate and depth of cut are too large Select a tougher grade P P2 P3 K K K2 Select an insert chipbreaker with a strong cutting edge Select a holder with a larger approach angle Select a holder with a larger shank size Reduce feed rate and depth of cut Adhesion/Built-up Edges Inappropriate grade selection Cutting edge is not sharp enough Cutting speed is too slow Feed rate is too slow Select a grade with less affinity to the work material Coated carbide or cermet grades Select a grade with a smooth coating Increase rake angle Reduce honing Increase cutting speed Increase feed rate Plastic Deformation Tool grade lacks thermal resistance Cutting speed is too fast Feed rate and depth of cut are too large ot enough coolant Select a more crater wear-resistant grade Increase rake angle Decrease cutting speed Reduce feed rate and depth of cut Supply sufficient coolant otch Wear Tool grade lacks wear resistance Rake angle is too small Cutting speed is too fast Select a more wear-resistant grade P3 P2 P K2 K K Increase rake angle Alter depth of cut to shift the notch location 4

5 Chip Control and Countermeasures, Turning Edition Type of Chip Generation Flowing Shearing Tearing Cracking Type of Chip Control Depth of cut A B C D E Influence factor Application Condition Type Work Material Continuous chips with good surface finish General cutting of steel and light alloy Large Large Small Large Work Material Chip is sheared and separated by the shear angle Steel, stainless steel (low speed) Work Material Chips appear to be torn from the surface Steel, cast iron (very low speed, very small feed rate) Deformation of work material Rake angle Depth of cut Cutting speed Work Material Chips crack before reaching the cutting point Cutting of general cast iron and carbon Small Small Large Small Classification Large of chip shapes Small C lathe (for automation) H H S S J General-purpose lathe (for safety) H S S S to J H Good: C type, D type A type: Twines around the tool or workpiece, damaging the machined { surface and affecting safety Poor B type: Causes problems in the automatic chip conveyor and chipping occurs easily E type: Causes spraying of chips and poor surface finish due to chattering, along with chipping, large cutting force and high temperatures Evaluation s Factor of Improvement of Chip Control () Increase feed rate (f ) t f t 2 f 2 Depth of Cut ap (mm) f:: When f 2 > f, t 2 > t When the feed rate increases, the chip thickness (t) increases and chip control improves Feed Rate f (mm/rev) (2) Decrease side cutting edge (:) f 2 t t 2 f When 2 <, t 2 > t Even if the feed rate is the same, a smaller side cutting edge angle makes chips thicker and chip control improves. Side Cutting Edge Feed Rate f (mm/rev) (3) Reduce nose radius (RE) f t RE Corner Large radius f t 2 t t 2 RE2 Corner Small radius RE: When RE2 < RE, t2 > t Even if the feed rate is the same, a smaller nose radius makes chips thicker and chip control improves. * Cutting force increases proportionately to the length of the contact surface. Therefore, a larger nose radius increases back force which induces chattering. A smaller nose radius produces a rougher surface finish at the same feed rate. ose Radius (mm) Depth of Cut a p (mm) 5

6 The Basics of Threading, Turning Edition Thread Cutting Methods s Cutting Method Radial Infeed Leading Edge Feed Direction Flank Infeed Trailing Edge Direction of Depth of Cut Features Most common threading technique, used mainly for small pitch threads. Easy to change cutting conditions such as depth of cut, etc. Long contact point has a tendency to chatter. Chip control is difficult. Considerable damage tends to occur on the trailing edge side. Effective for large-pitch threads and blemish-prone work material surfaces. Chips evacuate from one side for good chip control. The trailing edge side is worn, and therefore the flank is easily worn. Modified Flank Infeed Alternating Flank Infeed Effective for large-pitch threads and blemish-prone work material surfaces. Chips evacuate from one side for good chip control. Inhibits flank wear on trailing edge side. Effective for large-pitch threads and blemish-prone work material surfaces. Wears evenly on right and left cut edges. Since both edges are used alternately, chip control is sometimes difficult. Troubleshooting for Threading Failure Cause Countermeasures Excessive Wear Tool grade Select a more wear-resistant grade Cutting Edge Damage Uneven Wear on Right and Left Sides Cutting conditions Tool mounting Cutting conditions Reduce cutting speed Use a suitable quantity and concentration of coolant Change the number of passes Check whether the cutting edge inclination angle is appropriate for the thread lead angle Check whether the tool is mounted properly Change to modified flank infeed or alternating flank infeed Chipping Cutting conditions If built-up edge occurs, increase the cutting speed Breakage Biting of chips Supply enough coolant to the cutting edge Cutting conditions Increase the number of passes and reduce the depth of cut for each pass Use separate tools for roughing and finishing Shape and Accuracy Poor Surface Roughness Cutting conditions If blemished due to low-speed machining, increase the cutting speed If chattering occurs, decrease the cutting speed If the depth of cut of the final pass is too small, make it larger Tool grade Select a more wear-resistant grade Inappropriate cutting edge inclination angle Select the correct shim to ensure relief on the side of the insert Inappropriate Thread Shape Tool mounting Check whether the tool is mounted properly Shallow Thread Depth Shallow depth of cut Check the depth of cut Tool wear Check damage to the cutting edge 6

7 The Basics of Milling, Milling Edition Body diameter Boss diameter Bore Dia. Keyway Width Body Keyway Depth External cutting edge (Approach Angle) Ring Axial Rake Angle Fastener Bolt Face relief angle ring True Rake Angle Cutting edge Inclination angle Cutting edge angle Cutter height s Chip pocket Cutting edge indexable Insert A Cutter Diameter (ominal Diameter) Flank Relief Angle Clamp Plate Locator Enlarged Portion A ring Face Cutting Edge Angle External cutting edge (principal cutting edge) Radial Rake Angle Face cutting edge (Wiper Flat) Chamfered corner Milling Calculation Formulas Calculating cutting speed v c = n = X DC n, Calculating feed rate v f =f z z n f z =, v c X DC v f z n v c : Cutting speed (m/min) X : π 3.4 DC : ominal cutting diameter (mm) n : Rotation speed (min - ) v f : Feed rate per minute (mm/min) f z : Feed rate per tooth (mm/t) z : umber of teeth ap fz DC Milling Work Material Cutters n n vf vf Calculating power requirements Relation between feed rate, work material and specific cutting force P = a e a p v f k c = Q k c c 6 6 V 6 3 V Chip evacuation amount Q = a e a p v f, P c : Power consumption (kw) H : Required horsepower (HP) Horsepower requirements Q : Chip evacuation amount (cm 3 /min) P H = c.75 a e : Cutting width (mm) v f : Feed rate per minute (mm/min) a p : Depth of cut (mm) k c : Cutting force (MPa) Rough values Steel: 2,5 to 3,MPa Cast iron:,5mpa ( ) Aluminum: 8MPa V : Machine efficiency (about.75) Specific cutting force (MPa) o. Symbol Alloy Steel Carbon Steel Cast Iron Aluminum Alloy Work Material () Q (2) Q (3)..4 2 Q Figures in table indicate these characteristics. Alloy steel and carbon steel: Traverse rupture strength σ B (GPa) Cast iron: Hardness HB () Feed Rate (mm/t) (2) (3) () (2) (3) () (2) (3) 7

8 The Basics of Milling, Milling Edition s Functions of cutting edge angles Material Symbol Function Effect () (2) Axial rake angle Radial rake angle A.R. R.R. Determines chip evacuation direction, adhesion, thrust, etc. (3) Approach angle A.A. Determines chip thickness and chip evacuation direction Available in positive to negative (large to small) rake angles. Typical combinations: Positive and egative, Positive and Positive, egative and egative Large: Thin chips Small cutting force (4) True rake angle T.A. Effective rake angle Positive (Large): Excellent machinability and low chip adhesion. Low cutting edge strength egative (Small): Strong cutting edge and easy chip adhesion (5) Cutting edge inclination angle I.A. Determines chip control direction Positive (Large): Excellent chip control and small cutting force. Low cutting edge strength (6) Face cutting edge angle F.A. Determines surface finish roughness Small: Excellent surface roughness (7) Relief angle Determines cutting edge strength, tool life, chattering True rake angle (T.A.) table Inclination angle (I.A.) chart True rake angle T.A () (4) (2) -25 (3) Approach angle A.A. Example: () A.R. (Axial rake angle) = + -> (4) (2) R.R. (Radial rake angle) = -3 T.A. (True rake angle) = -8 (3) A.A. (Approach angle) = 6 } Radial rake angle R.R. Formula: tan T.A.=tan R.R./cos A.A. + tan A.R./sin A.A. Axial rake angle A.R Inclination angle I.A (2) (4) (3) Approach angle A.A. Example: () A.R. (Axial rake angle) = - -> (4) (2) R.R. (Radial rake angle) = +5 (3) A.A. (Approach angle) = 25 } I (inclination angle) = -5 Axial rake angle A.R. Formula: tan I.R.=tan A.R./cos A.A. - tan R.R./sin A.A. Radial rake angle R.R. Rake angle combination and features Edge combination and chip evacuation A.R. : Axial rake angle R.R : Radial rake angle A.A. : Approach angle : Chip and evacuation direction : Cutter rotation direction Advantages Disadvantages Applications A.A. (5 to 3 ) Double Positive type egative - Positive type Double egative type Good sharpness R.R. A.R. Pos. Pos. Only single-sided inserts with a lower cutting edge strength can be used Machining of aluminum alloy and other materials requiring sharpness A.A. (3 to 45 ) R.R. A.R. Pos. eg. Excellent chip evacuation and sharpness Only single-sided inserts can be used Machining of steel, cast iron, and stainless steel, with suitable strength and good evacuation A.A. (5 to 3 ) R.R. A.R. eg. eg. Economical design enabling use of both sides of insert Strong cutting edge Dull cutting action For hard materials such as cast iron or poor surfaces such as castings Cat. o. AX Type, WEZ Type, HF Type, WAX Type WGX Type, WFX Type, RSX Type, MSX Type TSX Type, DGC Type, DFC Type, DX Type Chips (Ex.) Work material: SCM435 v c =3m/min f z =.23mm/t a p =3mm 8

9 The Basics of Milling, Milling Edition Relation between engagement angle and tool life Work material feed direction (V f ) Cutting Width (W) Engagement Angle (E) DC Insert Milling Cutters Rotation direction The engagement angle denotes the angle at which the full length of the cutting edge comes in contact with the work material, with reference to the feed direction. The larger E is, the shorter the tool life To change the value of E: () Increase the cutter size (2) Shift the position of the cutter n Relation to cutter diameter Relation to cutter position Relation to tool life Relation between the number of simultaneously engaged cutting edges and cutting force Large diameter Tool Life (milling area) (m 2 ) vf E.4 vf E.3.2. Small E Small E DC n n S5C Engagement Angle Small diameter Tool Life (milling area) (m 2 ) vf vf E E n FC25 DC n Large E Large E Engagement Angle ormally, a cutting width 7 to 8% of the cutter diameter is considered appropriate, as shown in example d). However, this may not apply due to the actual rigidity of the machine or workpiece, and the machine horsepower. a) b) c) d) e) s Cutting force Time Cutting force Time Cutting force Time Cutting force Time Cutting force Time Work Material Milling Cutters or edge in contact at same time Only edge in contact at any time or 2 edges in contact 2 edges in contact at any time 2 to 3 edges in contact Improving surface roughness () Inserts with wiper flat When all of the cutting edges have wiper flats, a few teeth protrude due to inevitable runout and act as wiper inserts. Insert equipped with straight wiper flat (Face angle: Around 5' to ) Insert equipped with curved wiper flat (Curvature: R5 (example)) (2) Wiper insert assembling system A system in which one or two inserts (wiper inserts) protrude with a smooth curved edge just a little beyond the other teeth to wipe the milled surface. (Applicable to WGX Type, DGC Type, etc.) Surface roughness without wiper flat HC Surface roughness with straight wiper flat HF h: Projection value of wiper insert Cast Iron:.5mm ( Wiper Insert Al:.3mm ) ormal HW Edge Type h f: Feed rate per revolution (mm/rev) f f HC HW Hc: Surface roughness with only normal teeth Hw: Surface roughness with wiper insert Surface roughness with wiper edge (difference in face cutting edge) (A) (B) Effects of wiper insert (example) (C) (D) (Only normal teeth) Roughness ( μ m) (Wiper edge With wiper insert) Roughness ( μ m) Feed rate per tooth Feed rate per tooth Feed rate per tooth, 2 Feed rate per tooth 2,, 2 Feed per revolution Work material: SCM435 Cutter: DPG56R (per tooth) vc = 54m/min fz =.234mm/t ap = 2mm Face Cutting Edge Angle (A): 28 (B): 6 Work material: FC25 Cutter: DPG4R Insert: SPCH42R Face runout:.5mm Runout:.4mm vc = 5m/min fz =.29mm/t (.45mm/rev) (C): ormal teeth (D): Per wiper edge 9

10 Troubleshooting for Milling, Milling Edition Troubleshooting for Milling Failure Basic Remedies Countermeasure Examples s Excessive Flank Wear Tool Grade Select a more wear-resistant grade Carbide ( P3 P2 Coated K2 K ) { Cermet Cutting Decrease the cutting speed Conditions Increase feed rate Excessive Crater Wear Tool Grade Select a crater-resistant grade Tool Design Use a sharp chipbreaker (G L) Cutting Decrease the cutting speed Conditions Reduce depth of cut and feed rate Recommended Insert Grade Steel Cast Iron on-ferrous Alloy T25A, T45A ACK (Coated) Finishing DA (SUMIDIA) (Cermet) B7 (SUMIBORO) Roughing ACP (Coated) ACK2 (Coated) DL (Coated) Recommended Insert Grade Steel Cast Iron on-ferrous Alloy T25A, T45A Finishing (Cermet) ACK (Coated) DA (SUMIDIA) Roughing ACP (Coated) ACK2 (Coated) DL (Coated) Cutting Edge Damage Chipping Tool Grade Tool Design Cutting Conditions Use a tougher grade P P2 P3 K K K2 Select a negative/positive cutter with a large peripheral cutting edge angle (a small approach angle). Reinforce the cutting edge (honing) Change chipbreaker (G H) Reduce feed rate Recommended Insert Grade Steel Finishing ACP2 (Coated) Roughing ACP3 (Coated) Cast Iron ACK2 (Coated) ACK3 (Coated) Recommended cutter: SEC-WaveMill WGX Type Cutting conditions: Refer to H2 Breakage Tool Grade Tool Design Cutting Conditions If it is due to excessive low speeds or very low feed rates, select a grade resistant to chip adhesion If the cause is thermal cracking, select a thermal impact resistant grade Select a negative/positive (or double negative) cutter type with a large peripheral cutting edge angle (a small approach angle) Reinforce the cutting edge (honing) Change chipbreaker (G H) Increase insert size (thickness in particular) Select appropriate conditions for that particular application Recommended Insert Grade Steel Roughing ACP3 (Coated) Recommended cutter: SEC-WaveMill WGX Type Insert thickness: mm Change chipbreaker: Standard Strong edge type Cutting conditions: Refer to H2 Cast Iron ACK3 (Coated) Unsatisfactory Machined Surface Finish Tool Grade Tool Design Cutting Conditions Select an adhesion-resistant grade Carbide Cermet Improve axial runout of cutting edges Use a cutter with less runout ( Mount the correct insert ) Use a wiper insert Use cutters dedicated for finishing Increase the cutting speed Recommended Cutters and Insert Grades Steel Cast Iron on-ferrous Alloy General-purpose Finishing Cutter Insert Cutter Insert WGX Type* ACP2 (Coated) WGX Type T45A (Cermet) DGC Type ACK2 (Coated) FMU Type B7 (SUMIBORO) RF type * H (Carbide) DL (Coated Carbide) RF Type DA (SUMIDIA) Cutters marked with * can be mounted with wiper inserts. Others Chattering Tool Design Cutting Conditions Others Select a cutter with sharp cutting edges Use an irregular pitched cutter Reduce the feed rate Improve the rigidity of the workpiece and cutter clamp Recommended cutter For steel: SEC-WaveMill WGX Type For cast iron: SEC-Sumi Dual Mill DGC Type For light alloy: Aluminum Body Cutter RF Type Unsatisfactory Chip Control Tool Design Select a cutter with good chip evacuation features Reduce number of teeth Enlarge chip pocket Recommended cutter: SEC-WaveMill WGX Type Edge Chipping On Workpiece Tool Design Cutting Conditions Increase the peripheral cutting edge angle (decrease the approach angle) Change chipbreaker (G L) Reduce the feed rate Recommended cutter: SEC-WaveMill WGX Type Burr formation Tool Design Cutting Conditions Use a sharp cutter Increase feed rate Use a burr-proof insert Recommended cutter: SEC-WaveMill WGX Type + FG Chipbreaker SEC-Sumi Dual Mill DGC Type + FG Chipbreaker 2

11 The Basics of Endmilling, Endmilling Edition s O.D. Body Cutter sweep eck Head Diameter Shank eck length Cutting Edge Length Shank length Overall Length Shank Dia. Centre hole Land width Flank width Margin width Margin Radial flank Radial primary relief angle Radial secondary relief angle Land width Land Centre Cut Rake Face Groove With Centre Hole Rake Angle Helix Angle Corner Heel End cutting edge Peripheral Blade End gash Rounded flute bottom Centre hole Flute depth Web thickness Chip pocket Axial primary relief angle Axial secondary relief angle Ballnose Radius Concavity angle of end cutting edge (*) * Centre area is lower than the periphery Calculating cutting conditions (square endmill) Calculating cutting speed v c = X DC n, n =, v c X DC Side Milling Groove Milling Calculating feed rate per revolution and per tooth v f = n f f = v f n (Ballnose Endmill) v f = n f z z f z = f = z Calculating notch width (D ) v f n z a p a e DC DC ap D =2 2 RE a p - a p 2 Cutting speed and feed rate (per revolution and per tooth) are calculated using the same formula as the square endmill. RE pf Pick feed ap Depth of cut D ap DC pf RE D v c : Cutting speed (m/min) X : π 3.4 DC : Endmill diameter (mm) n : Spindle speed (min - ) v f : Feed rate (mm/min) f : Feed rate per revolution (mm/rev) f z : Feed rate per tooth (mm/t) z : umber of teeth a p : Depth of cut in axial direction (mm) a e : Depth of cut in radial direction (mm) RE : Ballnose radius 2

12 The Basics of Endmilling, Endmilling Edition s Up-cut and Down-cut Side Milling fz fz Slotting fz Work Material Work Material Work Material Up-cut side Down-cut side Work Material Feed Direction (a) Up-cut Work Material Feed Direction (b) Down-cut Work Material Feed Direction Work Material Work Material Feed Direction Work Material Work Material Feed Direction (a) Up-cut (b) Down-cut Cutting Edge Wear Amount Surface Roughness Cutting Conditions Flank Wear Width (mm) Up-cut Down-cut Cutting Length (m) Rz (μm) Feed Direction Roughness Up-cut Down-cut Vertical Direction Roughness Down-cut Up-cut Work material: S5C Tool: GSX2C-2D (ømm, 2 teeth) Cutting conditions: v c =88m/min (n=28min - ) v f =56mm/min (f z =.mm/t) a p =5mm a e =.5mm Side milling Dry, air Relation between cutting conditions and deflection Endmill specifications Side Milling Work Material: Pre-hardened steel (4HRC) Cutting Conditions: v c =25m/min Grooving Work Material: Pre-hardened steel (4HRC) Cutting Conditions: v c =25m/min a p =2mm a e =.8mm a p =8mm a e=8mm Up Cut side Down Cut side Feed Rate Feed Rate Feed Rate Feed Rate Cat. umber Helix.6mm/rev.mm/rev.5mm/rev.3mm/rev o. of Teeth Angle Style Style Style Style Up-cut Down-cut Up-cut Down-cut Up-cut Down-cut Up-cut Down-cut GSX28S-2D GSX48S-2D Machined surface surface Results The tool tip tends to back off with the down-cut. The side of the slot tends to cut into the up-cut side toward the bottom of the slot. The 4-flute type offers more rigidity and less backing off. The 4-flute type offers higher rigidity and less deflection. 22

13 Troubleshooting for Endmilling, Endmilling Edition Troubleshooting for Endmilling Failure Cause Countermeasures Excessive Wear Cutting Conditions Cutting speed is too fast Feed rate is too large Decrease cutting speed and feed rate Tool Shape The flank relief angle is too small Change to an appropriate flank relief angle s Cutting Edge Failure Others Chipping Fracture Deflection in Wall Surface Unsatisfactory Machined Surface Finish Chattering Chip Blockage Select a more wear-resistant substrate Use a coated tool Feed rate is too large Decrease cutting speed Depth of cut is too large Reduce depth of cut Tool overhang is too long Adjust tool overhang to the correct length Workpiece clamping is too weak Clamp the workpiece firmly Tool mounting is unstable Make sure the tool is seated in the chuck properly Feed rate is too large Decrease cutting speed Depth of cut is too large Reduce depth of cut Tool overhang is too long Reduce tool overhang as much as possible Cutting edge is too long Select a tool with a shorter cutting edge Tool Material Insufficient wear resistance Cutting Conditions Machine Area Cutting Conditions Tool Shape Web thickness is too small Change to more appropriate web thickness Feed rate is too large Decrease cutting speed Cutting Depth of cut is too large Reduce depth of cut Conditions Tool overhang is too long Adjust tool overhang to the correct length Cutting on the down-cut Change direction to up-cut Tool Shape Helix angle is too large Use a tool with a smaller helix angle Web thickness is too small Use a tool with the appropriate web thickness Feed rate is too large Decrease cutting speed Cutting Use air blow Conditions Biting of chips Use an insert with a larger relief pocket Cutting speed is too fast Decrease the cutting speed Cutting Cutting on the up-cut Change direction to down-cut Conditions Tool overhang is too long Adjust tool overhang to the correct length Tool Shape Rake angle is too large Use a tool with an appropriate rake angle Machine Workpiece clamps are too weak Clamp the workpiece firmly Area Tool mounting is unstable Make sure the tool is seated in the chuck properly Cutting Feed rate is too large Decrease cutting speed Conditions Depth of cut is too large Reduce depth of cut Tool Shape Too many teeth Reduce number of teeth Biting of chips Use air blow 23

14 Basics of Drilling, Drilling Edition of Drill Margin width Height of point Leading edge Back Taper s Margin Land width Chisel edge angle Flank Body clearance Flute Width Flute Chisel edge Blade Dia. Cutting edge Cutting edge Outer corner Lead Point angle Heel Helix Angle Body clearance Rake Face Flute Length Overall Length eck Taper shank Shank Length Shank Dia. Chisel edge corner Depth of body clearance Chisel edge length Diameter of body clearance Relief Angle Rake Angle B Web thinning A Point angle and force A:B or A/B = Groove width ratio Minimum requirement relief angle for drilling Relation between edge treatment and cutting force f: Feed rate (mm/rev) 8, T Md Point angle (small) Point angle and burr T Md Point angle (large) When point angle is large, thrust increases but torque decreases. DC DX x DX Effects of web thinning DC f Px=tan - π DX * A large relief angle is needed at the centre of the drill. f Torque (m) Thrust () 6, 4, 2, Feed Rate (mm/rev) Burr height (mm) Feed Rate (mm/rev) Work material: SS4 Cutting speed: v c =5m/min When point angle is large, burr height becomes low Thrust Thrust Removed Web thinning decreases the thrust concentrated at the chisel edge, makes the drill edge sharp, and improves chip control. Chisel width decreased by thinning Typical types of thinning Feed Rate (mm/rev) Drill : MultiDrill KDS25MAK Edge treatment width :.5mm.23mm Work material : S5C (23HB) Cutting conditions : v c =5m/min, wet 24 S Type Type X Type S Type: Standard type used for general purposes. Type: Suitable for thin web drills. X Type: For hard-to-cut materials or deep hole drilling. Entry easier.

15 Basics of Drilling, Drilling Edition of Power Requirements and Thrust Cutting Condition Selection Control cutting force for low-rigidity machines Power consumption (kw) f=. 3 f=. 2 f= Drill diameter (DC) (mm) Thrust () 2,, 8, 6, 4, 2, f: Feed rate (mm/rev) Work material: S48C (22HB) The following table shows the relation between edge treatment width and cutting force. If the cutting force is too great and causes issues, take measures such as reducing the feed rate or reducing the cutting edge treatment of the drill. Cutting Conditions Drill Diameter : ømm Edge treatment width Work material : S5C.5mm.5mm (23HB) v c (m/min) f (mm/rev) Torque (/m) Thrust () Torque (/m) Thrust () , , ,52 9.4, ,32 7.6, ,64 5.2, f=. 3 f=. 2 f= Drill diameter (DC) (mm) s High speed machining recommendation If the machine has enough power and sufficient rigidity, reasonable tool life can be ensured even when adopting higher efficiency machining; however, sufficient coolant must be supplied. Wear example Flank Rake Face Margin v c =6m/min v c =2m/min Work material : S5C (23HB) Cutting conditions : f =.3mm/rev H=5mm Tool life : 6 holes (Cutting length: 3m) Explanation of Margins (Difference between single and double margins) Single Margin (2 guides: part) Double Margin (4 guides: part) Shape used on most drills 4-point guiding reduces hole bending and undulation for improved stability and accuracy during deep hole drilling. 25

16 Basics of Drilling, Drilling Edition s Runout Accuracy Drill Mounting Peripheral Runout Accuracy For the runout accuracy of web-thinned drills, the runout after thinning (A) is important in addition to the difference in lip height (B). (A) (B) (A): Runout accuracy of thinning point (B): The difference of the lip height When the tool rotates The peripheral runout accuracy of the drill mounted on the spindle should be controlled within.3mm. If the runout exceeds the limit, the drilled hole will also become large and an increase in the horizontal cutting force, which may result in drill breakage. Runout: Within.3mm When the work material rotates The peripheral runout at the drill edge (A) and the concentricity at (B) should be controlled within.3mm. Hole expansion (mm) Centre runout A mm Peripheral runout B mm Peripheral runout mm. 5.9 Chuck MDS4MK S5C vc = 5m/min f =.3 mm/rev Hole expansion.3mm (A) (B) (Unit: mm). Cutting Force*.5 mm kg * Horizontal cutting force. Drill: MDS2MK, work material: S5C (23HB) Cutting Conditions: v c=5m/min, f =. 3mm/rev, H = 38mm Water-soluble Coolant Runout: Within.3mm Work Material Surface and Drill Performance Work material with slanted or uneven surface If the surface of the hole entrance or exit is slanted or uneven, decrease the feed rate to /3 to /2 of the recommended cutting conditions. (Entrance) (Exit) How to Use a Long Drill Problem When using a long drill (e.g. XHGS Type), SMDH-D Type drill or SMDH-2.5D Type drill at high rotation speeds, the runout of the drill tip may cause a deviation of the entry point as shown on the right, bending the drill hole and resulting in drill breakage. Remedies Method Hole bend Position shift Step Step 2 Step 3 Short drill xdc prepared hole machining (same diameter) n= to 3min - Method 2 *Low rotational speed minimises centrifugal forces and prevents the drill from bending. Step 2 to 3mm Step 2 2 to 3mm Drilling under recommended conditions (n= to 3min - ) f=.5 to.2mm/rev Drilling under recommended conditions 26

17 MultiDrill Usage Guidance, Drilling Edition Drill Maintenance Using Cutting Oil () Collet Selection and Maintenance Ensure proper chucking of drills to prevent vibration. Collet type chucks are recommended, as the grip is strong and can be used with ease. Drill chucks and keyless chucks are not suitable for MultiDrills as they have a weaker grip force. When replacing drills, regularly remove cutting chips inside the collet by cleaning the collet and the spindle with oil. Repair marks with an oilstone. (2) Drill Mounting The peripheral runout of the drill mounted on the spindle must be within.3mm. Do not chuck on the drill flute. If the drill flute is inside the holder, chip evacuation will be obstructed, causing damage to the drill. Collet Chuck Collet Collet Peripheral runout within.3mm Drill Chuck If there are marks, repair with an oilstone or change to a new one Do not grip on the drill flute () Choosing Cutting Oil If the cutting speed is more than 4m/min, cutting oil (JISW type 2) is recommended as its cooling effects and chip control capacity are good, and it is highly soluble. For optimum tool life at cutting speeds of less than 4m/min, sulfo-chlorinated oil (JISA type ) is recommended as it has a lubricating effect and is non-water soluble. * Insoluble cutting oil may be flammable. To prevent fire, a substantial amount of oil should be used to cool the component so that smoke and heat will not be generated. (2) Supply of Coolant External Coolant Supply There must be a sufficient external supply of coolant at the hole position. Coolant pressure.3 to.5mpa, coolant volume 3 to M/min is a guideline. Internal Coolant Supply For holes ø4 or smaller, the oil pressure must be at least.5mpa to ensure a sufficient supply of coolant. For ø6 and above, if L/D is <3, the pressures should be at.5 to.mpa. If L/D is >3, a hydraulic pressure of at least to 2MPa is recommended. External Coolant Supply Vertical drilling Use high pressure at entrance Horizontal drilling Internal Coolant Supply Coolant supply equipment Internal supply from machine Easy to use Use high pressure at entrance s Calculation of Power Consumption and Thrust Calculating cutting speed v c = n = X DC n,, v c X DC DC n H Hole Depth Clamping of the Workpiece High thrust forces occur during high-efficiency drilling. Therefore, the workpiece must be supported to prevent fractures caused by deformation. Large torques and horizontal cutting forces also occur. Therefore, the workpiece must be clamped firmly enough to withstand them. Deformation chipping Especially large drills Support needed Calculating feed rate per revolution and per tooth v c : Cutting speed (m/min) v f = n f f = v f n Calculation of Cutting Time T = H v f Calculation of Power Consumption and Thrust <Experimental> Power consumption (kw) = HBDC v c f.59 /36, Thrust ()=.24HBDC.95 f X : π 3.4 DC : Drill diameter (mm) n : Rotation speed (min - ) v f : Feed rate (mm/min) f : Feed rate per revolution (mm/rev) H : Drilling depth (mm) T : Cutting time (min) HB : Work material Brinell hardness * When designing the machine, an allowance of.6 x power consumption and.4 x thrust should be given. Drill Regrinding When to regrind When one or two feed marks (lines) appear on the margin, when corner wear reaches the margin width or when small chipping occurs, it indicates that the drill needs to be sent for regrinding. How and where to regrind We recommend regrinding and recoating. Regrinding alone may be sufficient, but if the work material is steel, use recoating as well as regrinding to prevent shortening of tool life. ote: Ask us or an approved vendor to recoat with our proprietary coating. Regrinding on your own Customers regrinding their own drills can obtain MultiDrill Regrinding Instructions from us directly or their vendor. Tool life determinant to 2 feed marks Appropriate Tool Life Excessive marks Over-used 27

18 Troubleshooting for Drilling, Drilling Edition Troubleshooting for Drilling Failure Cause Basic Remedies Countermeasure Examples s Drill Failure Unsatisfactory Hole Accuracy Unsatisfactory Excessive Wear on Rake Face Chisel Point Breakage Breakage on Peripheral Cutting Edge Margin Wear Drill Breakage Oversized Holes Poor Surface Roughness Holes are not straight Long Stringy Chips Inappropriate cutting Use higher cutting speeds Refer to the upper limit of the recommended cutting conditions listed in the IGETALLOY Cutting Tools Catalogue conditions Increase feed rate Refer to the upper limit of the recommended cutting conditions listed in the IGETALLOY Cutting Tools Catalogue Unsuitable coolant Reduce pressure if using internal coolant.5mpa or less (external coolant supply can be used at hole depths (L/D) of 2 or less) Use coolant with more lubricity Use JIS A grade o. or its equivalent Off-centre starts Reduce feed rate at entry point f=.8 to.2mm/rev Pre-machining of flat surface for entry Drill flat base with Flat MultiDrill Equipment, work materials, Change cutting conditions to reduce resistance Increase v c to decrease f (reduce thrust) etc. lack rigidity Improve clamp strength of work material Cutting edge is too Increase size of chisel width Use a chisel with a width of. to.2mm weak Increase amount of honing on cutting edge Increase the width of the thinning area at the centre by.5 times Inappropriate cutting Decrease the cutting speed Refer to the lower limit of the recommended cutting conditions listed in the IGETALLOY Cutting Tools Catalogue conditions Reduce feed rate Refer to the lower limit of the recommended cutting conditions listed in the IGETALLOY Cutting Tools Catalogue Unsuitable coolant Use coolant with more lubricity Use JIS A grade o. or its equivalent Equipment, work materials, etc. lack rigidity Improve clamp strength of work material Cutting edge is too Increase amount of honing on cutting edge Increase the width of the outer cutting edge by.5 times weak Reduce the front relief angle Reduce the front relief angle by 2 to 3 Entry from peripheral cutting edge Increase margin width (W margin specification) Increase the margin width by 2 to 3 times Reduce feed rate Refer to the lower limit of the recommended cutting conditions listed in the IGETALLOY Cutting Tools Catalogue Interrupted through Increase amount of honing on cutting edge Increase the width of the outer cutting edge by.5 times cutting Reduce the front relief angle Reduce the front relief angle by 2 to 3 Inappropriate cutting conditions Decrease the cutting speed Refer to the lower limit of the recommended cutting conditions listed in the IGETALLOY Cutting Tools Catalogue Unsuitable coolant Use coolant with more lubricity Use JIS A grade o. or its equivalent Use more coolant If using external coolant, switch to internal coolant Remaining margin wear Schedule for earlier regrind and ensure back taper If margin damage occurs, regrind to mm or less Improper tool design Increase amount of back taper Make back taper.5/ Reduce margin width Reduce the margin width to around 2/3 Chip blockage Use the optimal cutting conditions and tools Refer to recommended cutting conditions listed in the IGETALLOY Cutting Tools Catalogue Use more coolant If using external coolant, switch to internal coolant Holding clamp too weak Use strong holding clamp Equipment, work materials, etc. lack rigidity Improve clamp strength of work material If the collet chuck is damaged, replace it Change the collet holder to the next size up Reduce feed rate at entry point f=.8 to.2mm/rev Off-centre starts Decrease the cutting speed Refer to the lower limit of the recommended cutting conditions listed in the IGETALLOY Cutting Tools Catalogue Pre-machining added for entry in planar surfaces Planar machining with endmill Drill bit lacks rigidity Use the optimal drill type for the hole depth Refer to the IGETALLOY Cutting Tools Catalogue Improve overall drill rigidity Large web, small groove width Drill bit has runout Improve drill mounting precision If the collet chuck is damaged, replace it Improve drill retention rigidity Change the collet holder to the next size up Equipment, work materials, etc. lack rigidity Improve clamp strength of work material Inappropriate cutting Increase the cutting speed Refer to the upper limit of the recommended cutting conditions listed in the IGETALLOY Cutting Tools Catalogue conditions Reduce feed rate Refer to the lower limit of the recommended cutting conditions listed in the IGETALLOY Cutting Tools Catalogue Unsuitable coolant Use coolant with more lubricity Use JIS A grade o. or its equivalent Off-centre starts Increase feed rate Refer to the upper limit of the recommended cutting conditions listed in the IGETALLOY Cutting Tools Catalogue Drill is not mounted Improve drill mounting precision If the collet chuck is damaged, replace it properly Improve drill retention rigidity Change the collet holder to the next size up Equipment, work materials, Improve clamp strength of work material etc. lack rigidity Select a double margin tool Refer to the IGETALLOY Cutting Tools Catalogue Increase cutting speeds Refer to the upper limit of the recommended cutting conditions listed in the IGETALLOY Cutting Tools Catalogue conditions Increase feed rate Refer to the upper limit of the recommended cutting conditions listed in the IGETALLOY Cutting Tools Catalogue Poor chip evacuation Increase volume if using internal coolant Inappropriate cutting Increase feed rate Refer to the upper limit of the recommended cutting conditions listed in the IGETALLOY Cutting Tools Catalogue conditions Increase cutting speeds Refer to the upper limit of the recommended cutting conditions listed in the IGETALLOY Cutting Tools Catalogue Strong cooling effect Reduce pressure if using internal coolant The pressure should be.5 MPa or less if using internal coolant Dull cutting edge Reduce amount of edge honing Reduce the width to around 2/3 Chip Control Chips clog Inappropriate cutting 28

19 Hardened Steel Machining with SUMIBORO, SUMIBORO Edition Recommended Zones for SUMIBORO by Workpiece Hardness and Shape Cutting speed recommendations for each work material Interrupted Cutting Heavy Light Continuous Cutting Coated carbide Cermet Ceramic SUMIBORO Hardness of work material (HRC) Cutting Speed (m/min) 3 2 Carburised or induction hardened material Bearing Steel Die Steel Prone to notch wear Fairly large amount of wear Large amount of wear s Influence of coolant on tool life Continuous Cutting Flank Wear Width (V B ) (mm) Dry Oil-based coolant Water soluble emulsion Water soluble 2 Work material: SUJ2(58 to 62 HRC) Cutting conditions: TPG634 vc=m/min, ap=. 5mm, f=. mm/rev Continuous Cutting In continuous cutting of bearing steel, there is not much difference between dry and wet cutting Cutting Time (min) Interrupted Cutting Milling of SKD to 4 U grooves Cutting speed: vc=m/min Depth of cut: ap=.2 mm Feed rate (f )=. mm/rev Tool Life 5 Heavy Interrupted Cutting Dry Wet cut For continuous cutting, the influence of coolant on tool life is minimal. For interrupted cutting, the thermal impact shortens the tool life in wet conditions. Relation between work material hardness and cutting force Cutting force () 5 5 Principal Force Feed Force Back Force Hardness of Work Material (HRC) Back force increases substantially for harder workpieces. Principal Force Feed Force Back Force Work Material: SK3 Cutting Conditions: Cutting speed (vc) =2m/min, depth of cut (ap) =.2mm Feed rate (f ) =. mm/rev Relation between flank wear and cutting force Influence of work material hardness on cutting force and accuracy Back force () Principal Force () Feed force () 3 2 SCM43 65HRC S55C 24HRC.5. Flank Wear Width (VB) (mm) Cutting conditions: Cutting speed (vc) = 8 m/min Depth of cut (ap) =.5mm Feed rate (f ) =.mm/rev For hardened steel machining, back force increases substantially due to the expansion of flank wear. Dimensions (μm) Back force () Shore hardness (HS) Hard zone Soft zone Hard zone Work material: S38C 45HS 6 3μm Cutting Speed : Depth of Cut : Feed Rate : vc = 2m/min ap =.5mm f =.3mm/rev, dry External dimensions in the soft zone are smaller due to lower cutting forces. Relation between cutting speed and surface roughness Surface Roughness (Ra) (μm).3.2. B25 Vc=2 B25 Vc=5 B25 Vc=8 Work material : SCM42H 58 to 62HRC Holder : MTXR2525 Tool : U-TMA648 Cutting Conditions: vc =2,5,8m/min f =.45mm/rev ap =.5mm Wet Improvement of surface roughness by altering the feed rate Constant Feed Rate Variable Feed Rate Previous Edge Position f f Stationary otch Location Shifting otch Location Machining Output (pcs.) At high cutting speeds, surface roughness is more stable. Varying the feed rate spreads the notch location over a larger area. Surface finish improves and notch wear decreases. 29

20 High Speed Machining of Cast Iron with SUMIBORO, SUMIBORO Edition Advantages of using SUMIBORO for cast iron machining Higher accuracy Longer tool life at higher cutting speeds Gray Cast Iron Ductile Cast Iron s Dimensional Tolerance, Good Cutting Speed (m/min) BS8 B7 BC5 Ceramic Coated carbide Cermet Good Surface Roughness Standard Ra (μm) 5 2 Ceramic Coated carbide Cermet BS8 B7 B5 2 Tool Life Ratio Cutting Speed (m/min) 5 2 Ceramic Coated carbide Cermet Tool Life Ratio BX BC5 B7 Turning Cast iron structure and wear shape examples FC FCD Structure Matrix Pearlite Pearlite + Ferrite Flank Wear Width (VB) (mm) Work material : Continuous cutting Dry with FC25 Wet (water soluble) Tool material : B5 Tool Shape : SG248 Cutting Conditions : vc =45m/min ap=.25mm f =.5 mm/rev Dry & Wet (water soluble) Cutting Length (km) Surface Roughness (Rz) (μm) Cutting speed (vc) (m/min) Tool wear shape Wet Dry Crater wear (v c =2 to 5m/min) WET (Water soluble) DRY For turning cast iron with SUMIBORO, cutting speeds (v c ) should be 2m/min and above. Wet cutting is recommended. Machine : /C lathe Work Material : FC25 2HB Holder : MTJP2525 Tool Grade : B5 Tool Shape : TMA648 Cutting Conditions : vc= to 28m/min f =. mm/rev ap=.mm Wet Milling B Finish Mill EASY (for high-speed finishing of cast iron) Enables cutting with v c of 2,m/min Surface finish roughness 3.2Rz (.Ra) Economical insert reduces running costs. Unit style enables easy runout adjustment. Employs safe, anti-centrifugal-force construction for high-speed conditions. Flank Wear Width (mm) Ceramic vc = 4m/min Ceramic vc = 6m/min vc = 6m/min vc =,m/min vc =,5m/min umber of passes Cutting Conditions ap=.5mm, fz=.5mm/t Dry Thermal cracks occur umber of passes (Pass) 3 Wet ,5,2,35,5 Cutting Speed (m/min) Work material: Gray cast iron (FC25) Cutting conditions: ap =.5mm, fz =.mm/t dry Tool grade: B7 Dry cutting is recommended for high speed milling of cast iron with SUMIBORO. 3

21 Machining Exotic Alloys with SUMIBORO, SUMIBORO Edition Powdered Metal SUMIBORO Cemented Carbide Cermet. Flank wear 2. Surface roughness 3. Height of burr Flank Wear Width (mm) Cutting Speed (m/min) Work material: Equivalent to SMF44, ø8-ømm heavy interrupted facing with grooves and drilled holes. (After 4 passes) Cutting conditions: f=.mm/rev, ap=.mm Wet Tool Cat. o.: TGA644 Heat-Resistant Alloy ickel based alloy Typical tool damage of CB tool when cutting Inconel 78 Influence of cutting speed (Tool grade BX2, f =.6mm/rev, L=.72km) vc =3m/min vc =5m/min otch Wear Flank Wear Flank Wear Influence of feed rate (Tool grade BX2, vc=3m/min, L=.8km) f =.2 mm/rev f =.6 mm/rev otch Wear Flank Wear Influence of tool grade (vc=5m/min, f =.2 mm/rev. L=.36km) BX2 B7 otch Wear Flank Wear Cutting Conditions: ap=.3mm, Wet. 5mm Surface Roughness Rz (μm) Cutting Speed (m/min) Cutting Speed (m/min) Enables cutting at vc of up to m/min even with cemented carbide. However, if vc is around 2m/min or higher, wear occurs rapidly, resulting in poorer surface roughness and greater spread of burrs. On the other hand, SUMIBORO exhibits stability and superior wear resistance, burr prevention and surface roughness, especially at high speeds. Cutting Speed (m/min) Cutting conditions: f =.6mm/rev, ap=.3mm, wet B7 2 BX2 Whisker reinforced ceramic Cutting Length (m) Tool life criteria otch wear =.25mm ( ) or flank wear =.25mm BX2 is recommended for high speed and low feed rates; B7 is recommended for cutting speeds below vc = 24m/min. Maximum Height of Burr (mm) Cutting Speed (m/min) Cutting conditions: f =.2mm/rev, ap=.3mm, wet 2 3 Cutting Length (m) B7 BX2 Whisker reinforced ceramic Coated carbide (K class) Tool life criteria otch wear =.25mm ( ) or flank wear =.25mm B7 is recommended for cutting at high feed rates (over f =.mm/rev). s Ti based alloy Flank Wear Width (vb) (mm).2 B7 breakage Cutting Time (min) Work material: Ti-6A-4V Tool: F-DMX244 Cutting Conditions: vc=m/min, ap=. mm, f=. 5mm/rev Wet Our ultra-sharp positive SUMIDIA inserts have a strong cutting edge and excellent wear resistance Hard Facing Alloys Carbide (K) DA5 Flank Wear Width (vb) (mm) B7 breakage Carbide (K) DA5 5 5 Cutting Time (min) Work material: Ti-6A-4V Tool: F-DMX244 Cutting Conditions: vc=m/min, ap=. mm, f=. 5mm/rev Wet Our ultra-sharp positive SUMIDIA inserts have a strong cutting edge and excellent wear resistance Flank Wear Width (vb) (mm).2 DA5 Breakage.5..5 B Cutting Time (min) Work material: Ti-6Al-4V Tool: DMA542 Cutting Conditions: vc=2m/min, ap=. 3mm, f=. 25mm/rev Wet Highly fracture-resistant B7 negative insert is suitable for highefficiency machining with large depth of cut and high feed rate. Work Material: Colmonoy o.6 (icr-based self-fluxing alloy) Work Material: Stellite SF-2 (Co-based self-fluxing alloy) Tool Cat. o. : SG938 Cutting conditions : vc=5,3m/min f =. mm/rev ap=.2mm Dry Flank Wear Width (mm) BS8 (v c =3m/min).5 Whisker reinforced ceramic (v c =5m/min).4 Cutting is effectively impossible because of the large degree of wear even at v c = Minimal wear at v c =3m/min Cutting Distance (km) Whisker reinforced ceramic (vc =5m/min, after.km of cutting) BS8 (vc =3m/min, after km of cutting) Tool Cat. o. : SG938 Cutting conditions : vc=5m/min f =. mm/rev ap=.2mm Dry Flank Wear Width (mm) Chipping BS8 Competitor's Solid CB.2 o chipping Cutting Distance (km) Chipping Competitor's Solid CB (After 2km of cutting) BS8 (After 2km of cutting) 3

22 Cutting Edge Failure and Countermeasures when Machining Hardened Steel, SUMIBORO Edition s Insert Failure Cause Countermeasures Flank Wear Crater Wear Grade lacks wear resistance Cutting speed is too fast Grade lacks crater wear resistance Select a more wear-resistant grade (eg BC2, B or B2) Reduce the cutting speed to v c =2m/min or less (higher feed rate also reduces tool-to-work contact time) Use an insert with a larger relief angle Select a higher efficiency grade (eg BC2, BX25 or BX2) Breakage at Bottom of Crater Cutting speed is too fast Reduce the cutting speed to v c =2m/min or less and increase the feed rate (low speed, high feed) (higher feed rate alone also reduces tool-to-work contact time) Flaking Grade lacks toughness Select a tougher grade (eg BC22 or B2) otch Wear Chipping at Forward otch Position Chipping at Side otch Position Thermal Crack Back force is too high High stress at boundary Impact to front cutting edge is too large or occurs constantly Impact to side cutting edge is too large or occurs constantly Select an insert with a stronger cutting edge (Increase negative land angle and perform honing) If the grade is tough enough, improve the cutting edge sharpness Change to a grade with a higher notch wear resistance (e.g. BC2 or B2) Increase cutting speed (5 m/min or more) Change to the Variable Feed Rate method, which alters the feed rate in fixed output intervals Increase negative land angle and perform honing Change to a micro-grained grade with a higher fracture resistance (e.g. BC3 and B35) Increase the feed rate (higher feed rates are recommended to reduce chipping) Select an insert with a stronger cutting edge (Increase negative land angle and perform honing) Change to a grade with a higher fracture resistance (e.g. B35 or BC3) Reduce feed rate Use an insert with a larger side cutting angle Use an insert with a larger nose radius Select an insert with a stronger cutting edge (Increase negative land angle and perform honing) Completely dry conditions are recommended Thermal shock is too severe Select a grade with better thermal conductivity Reduce cutting speed, feed rate, and depth of cut to decrease the machining load. 32