AUDIT CRITERIA. Superseding AC7116/3 Nadcap AUDIT CRITERIA FOR ELECTRICAL DISCHARGE MACHINING (EDM)

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1 AC7116/3 REV. A 161Thorn Hill Road Warrendale, PA AUDIT CRITERIA Issued Revised Superseding AC7116/3 Nadcap AUDIT CRITERIA FOR ELECTRICAL DISCHARGE MACHINING (EDM) 1. SCOPE This checklist is to be used as a supplement to PRI AC7116 for suppliers seeking accreditation for electrical discharge machining (EDM). Audits should not be performed in operations where EDM is used as a preliminary machining operation and subsequent methods are used to remove all traces of the EDM operation. Audits shall not be performed on process set-up instructions when they are part of the workstation instructions. 2. GENERAL INFORMATION Questions noted with (Info) are asked for information purposes only. For (Info) questions, answers do not require the issuance of an NCR or an explanation. N/A (Not Applicable) answers to questions will be permitted only to the extent defined in the Auditor Handbook. Auditor Scope The scope of this audit includes AC7116 and the following processes audited: Electrical Discharge Machining Wire EDM Sinker EDM Using Oil Dielectric Fluid Sinker EDM Using Water Based Dielectric Fluid Fast Hole EDM PRI operating procedures provide that "This report is published by PRI to advance the state of technical, engineering, and quality sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user." PRI invites your written comments and suggestions. Copyright 2009 Performance Review Institute. All rights reserved. t-frm-15 7-Jan-09

2 PRI AC7116/3 Revision A EQUIPMENT 3.1 Verification of EDM Power Supplies a) Does the supplier have a plan to annually verify the operation of each EDM power supply or calibrate meters and gages on the power supply? b) Does the calibration program cover conductivity measuring devices for water based dielectric systems? c) Does the supplier have a procedure for identifying and labeling all reference gages? d) Does the supplier s calibration plan cover external capacitors for manual or computer controlled supplies? N/A N/A N/A 3.2 Maintenance Does the supplier have an EDM machine preventative maintenance program that includes the following: a) EDM dielectric system? b) EDM machine? c) EDM power supply? Has the preventative maintenance program been completed as per schedule, and are records available to verify completion? 3.3 Do all EDM dielectric fluid and electrode material meet customer requirements? 4. WORK INSTRUCTION REQUIREMENTS 4.1 EDM Equipment a) Do the workstation instructions list the power supply model? 4.2 Fixtures and Support Material Fixtures a) Are the fixtures listed by identification number(s), code(s), or by a description when no tool number is available? Fixture Acceptance a) If fixture control is used for acceptance of parts, does the supplier have a program to periodically check the fixturing? N/A Electrodes a) For sinker EDM, are electrodes listed by a drawing and revision number, or unique configuration and material? b) For wire EDM, is the specific wire catalog number or type (base material and coating type if applicable), and size listed? N/A N/A

3 PRI AC7116/3 Revision A Electrode Dressing a) Is equipment and the process used for electrode dressing listed when electrode dressing is performed as part of the EDM operation? N/A 4.4 Machining Operations per Electrode a) Are the number or EDM machining operations per electrode or the allowable electrode wear specified in the workstation N/A 4.5 Work Instruction Approval a) Are work instructions approved in accordance with supplier requirements? b) Are work instructions approved in accordance with customer requirements? N/A 4.6 EDM Power Supply Parameter Requirements Manual EDM Machines a) Do the workstation instructions list a setting or range for every control or gage on the EDM machine power supply? b) On EDM power supplies where multiple leads can be used, do the workstation instructions list the number of power supply leads connected to the fixtures? c) Do the workstation instructions list the electrode polarity or describe how the EDM machine power supply should be connected? N/A N/A Computer Controlled EDM Machines a) Do the workstation instructions list the machine part program name or number with revision level? b) Do the workstation instructions list a setting or range for every control or gage on the EDM power supply not controlled by the machine part program? N/A N/A 4.7 EDM General Requirements Do the workstation instructions describe: a) Dielectric flushing method? b) Part loading and verification method? 3 Electrode loading and verification method? d) Dielectric fluid electrical conductivity limits? N/A e) Dielectric fluid used including any additives added to water or oil dielectric fluids N/A together with the amount or concentration used? f) Number or range of parts produced simultaneously, if greater than one part? N/A g) Settings for any external capacitors or capacitor boxes? N/A

4 PRI AC7116/3 Revision A QUALITY PLANS 5.1 Procedure Does the quality plan cover the following items: a) EDM generated dimensions to be checked? b) Method of control for each dimension or characteristic? (i.e., fixture, gages and/or inspection instruments, electrode, machine program) c) Frequency of inspection? d) Examination of part electrical points, and the EDM machined are for arcing? 5.2 Quality Approval Plan a) Has the quality plan, including sampling, been approved in accordance with customer requirements? 6. METALLOGRAPHIC EVALUATION 6.1 Does the supplier s quality plan require that initial metallographic testing is performed to verify compliance to applicable drawing notes and/or related specifications? 6.2 Does the supplier have a plan to perform periodic metallographic tests as per customer requirements? 6.3 Does the supplier s plan to perform initial and periodic metallographic tests require that the same parameters used in workstation instructions be used to produce metallographic samples? 6.4 Does the supplier s quality plan define acceptable samples used for the metallographic testing? 6.5 Does the supplier s quality plan require that customer approved laboratories are used to perform metallographic testing? N/A N/A N/A N/A N/A 6.6 Is metallographic testing on processed parts conducted by an approved source? N/A In-house check the one sub-question that applies Nadcap accredited to AC7101/4 or AC7109/5 Record: Certification # Issue Date Expiration Date Initially approved by Nadcap subscribing customer. Record: Customer Name Approval Date

5 PRI AC7116/3 Revision A Outside source check the one sub-question that applies Record: Subcontract metallographic facility (name and address) Nadcap accredited to AC7101/4 or AC7109/5 Record: Certification # Issue Date Expiration Date Initially approved by Nadcap subscribing customer. Record: Customer Name Approval Date 7. TRAINING 7.1 Does the supplier have an EDM operator training program?

6 PRI AC7116/3 Revision A JOB AUDIT #1 Process Method: 8.1 Customer Requirements Complete the following and then check the supplier s information (i.e., technique sheets, travelers) against the purchasing requirements. a) Job Identity/Number: b) Operation Number: c) Drawing Number and Revision: d) Part Description: e) Does the supplier have a drawing that matches the drawing number and revision listed on the purchase order? f) Customer: g) Purchase Order/Revision Level: h) Specification (where applicable): i) Does the part serial number match the serial number on the shop traveler/router? N/A j) Were all job operations performed in the proper sequence, and signed off or stamped verifying completion? 8.2 Operator Qualification a) Has the EDM operator(s) received required training and has training been documented? 8.3 EDM Equipment a) Are all EDM power supply controls that the operator has access to operational/functional? b) Has the EDM machine, dielectric system, and power supply been maintained per the supplier s preventative maintenance plan? c) Have all meters and gages been calibrated, on EDM machines according to the N/A supplier s calibration plan? d) Are conductivity measuring devices for water based dielectric calibrated? N/A e) Are gages that are used for reference only labeled accordingly? N/A f) Has the EDM power supply operation been verified or all power supply meters and gages calibrated per supplier s plan? g) Is the EDM dielectric fluid listed in the workstation instructions, or general EDM instructions, the same fluid used in the EDM machine? h) Is the electrical conductivity of the EDM water dielectric fluid within limits in the N/A workstation instructions or in a supplier controlling document? i) Are any external capacitors or capacitor boxes calibrated and do they have a calibration sticker attached? N/A

7 PRI AC7116/3 Revision A Workstation Instructions a) Are workstation instructions available at the workstation? b) Is the EDM operation being performed on the same type of EDM power supply listed in the workstation c) Are the fixture identification number(s), code(s) or description listed in the workstation instructions the same as that used in the EDM machine? d) Are tools, gages and fixtures that the operator is using listed in the workstation e) For sinker EDM, is the electrode(s) listed in the workstation instructions the same N/A as those used at the EDM machine? f) For wire EDM, is the specific wire type and size listed in the workstation N/A instructions the same as that used at the EDM machine? g) If electrode dressing is done as part of the EDM operation, is the electrode dressing equipment listed in the workstation instructions the same as the equipment used at the EDM workstation? N/A h) Is the operator following the workstation instructions listing the number of cuts per electrode or allowable electrode wear before re-dress or electrode replacement? i) Are all of the controls on the EDM power supply set within limits listed in the workstation instructions or within the part program (including revision level) referenced in the workstation N/A j) Is the EDM machine set to the correct polarity as detailed in the workstation k) Are external capacitors or capacitor boxes set within limits listed in the workstation N/A l) When multiple leads are used are they connected per the workstation N/A m) Is the dielectric flushing method on the machine the same as it is described in the workstation n) Is the operator following the part loading and verification method described in the workstation o) Is the operator following the electrode loading and verification method described in the workstation p) Is the EDM operator machining the correct number or range of parts simultaneously as described in the workstation q) Does the part program name or number on the work instructions match the current program and revision level used? r) Have the EDM workstation instructions been approved according to the supplier s internal procedure? s) Have the EDM workstation instructions been approved by the customer? N/A t) Is the operator following the workstation u) If fixture control is used for part acceptance, has the fixture been calibrated? N/A 8.5 Part Cleaning Do pre and post cleaning methods used conform to the customer requirements? N/A

8 PRI AC7116/3 Revision A Part Inspection a) Are the gage(s) and/or measuring devices used within calibration time limits? b) Are all of the measurements described in the workstation instructions being performed at the required frequency? c) Is the supplier visually inspecting all parts for EDM arcing that includes examination of part electrical contact points, and the EDM machined area? d) Are the gages and/or inspection instruments used to inspect parts the same as those listed in the workstation

9 PRI AC7116/3 Revision A JOB AUDIT #2 N/A Process Method: 9.1 Customer Requirements Complete the following and then check the supplier s information (i.e., technique sheets, travelers) against the purchasing requirements. a) Job Identity/Number: b) Operation Number: c) Drawing Number and Revision: d) Part Description: e) Does the supplier have a drawing that matches the drawing number and revision listed on the purchase order? f) Customer: g) Purchase Order/Revision Level: h) Specification (where applicable): i) Does the part serial number match the serial number on the shop traveler/router? N/A j) Were all job operations performed in the proper sequence, and signed off or stamped verifying completion? 9.2 Operator Qualification a) Has the EDM operator(s) received required training and has training been documented? 9.3 EDM Equipment a) Are all EDM power supply controls that the operator has access to operational/functional? b) Has the EDM machine, dielectric system, and power supply been maintained per the supplier s preventative maintenance plan? c) Have all meters and gages been calibrated, on EDM machines according to the supplier s calibration plan? N/A d) Are conductivity measuring devices for water based dielectric calibrated? N/A e) Are gages that are used for reference only labeled accordingly? N/A f) Has the EDM power supply operation been verified or all power supply meters and gages calibrated per supplier s plan? g) Is the EDM dielectric fluid listed in the workstation instructions, or general EDM instructions, the same fluid used in the EDM machine? h) Is the electrical conductivity of the EDM water dielectric fluid within limits in the workstation instructions or in a supplier controlling document? i) Are any external capacitors or capacitor boxes calibrated and do they have a calibration sticker attached? N/A N/A

10 PRI AC7116/3 Revision A Workstation Instructions a) Are workstation instructions available at the workstation? b) Is the EDM operation being performed on the same type of EDM power supply listed in the workstation c) Are the fixture identification number(s), code(s) or description listed in the workstation instructions the same as that used in the EDM machine? d) Are tools, gages and fixtures that the operator is using listed in the workstation e) For sinker EDM, is the electrode(s) listed in the workstation instructions the same N/A as those used at the EDM machine? f) For wire EDM, is the specific wire type and size listed in the workstation N/A instructions the same as that used at the EDM machine? g) If electrode dressing is done as part of the EDM operation, is the electrode dressing equipment listed in the workstation instructions the same as the equipment used at the EDM workstation? N/A h) Is the operator following the workstation instructions listing the number of cuts per electrode or allowable electrode wear before re-dress or electrode replacement? i) Are all of the controls on the EDM power supply set within limits listed in the workstation instructions or within the part program (including revision level) referenced in the workstation N/A j) Is the EDM machine set to the correct polarity as detailed in the workstation k) Are external capacitors or capacitor boxes set within limits listed in the workstation N/A l) When multiple leads are used are they connected per the workstation N/A m) Is the dielectric flushing method on the machine the same as it is described in the workstation n) Is the operator following the part loading and verification method described in the workstation o) Is the operator following the electrode loading and verification method described in the workstation p) Is the EDM operator machining the correct number or range of parts simultaneously as described in the workstation q) Does the part program name or number on the work instructions match the current program and revision level used? r) Have the EDM workstation instructions been approved according to the supplier s internal procedure? s) Have the EDM workstation instructions been approved by the customer? N/A t) Is the operator following the workstation u) If fixture control is used for part acceptance, has the fixture been calibrated? N/A 9.5 Part Cleaning Do pre and post cleaning methods used conform to the customer requirements? N/A

11 PRI AC7116/3 Revision A Part Inspection a) Are the gage(s) and/or measuring devices used within calibration time limits? b) Are all of the measurements described in the workstation instructions being performed at the required frequency? c) Is the supplier visually inspecting all parts for EDM arcing that includes examination of part electrical contact points, and the EDM machined area? d) Are the gages and/or inspection instruments used to inspect parts the same as those listed in the workstation

12 PRI AC7116/3 Revision A JOB AUDIT #3 N/A Process Method: 10.1 Customer Requirements Complete the following and then check the supplier s information (i.e., technique sheets, travelers) against the purchasing requirements. a) Job Identity/Number: b) Operation Number: c) Drawing Number and Revision: d) Part Description: e) Does the supplier have a drawing that matches the drawing number and revision listed on the purchase order? f) Customer: g) Purchase Order/Revision Level: h) Specification (where applicable): i) Does the part serial number match the serial number on the shop traveler/router? N/A j) Were all job operations performed in the proper sequence, and signed off or stamped verifying completion? 10.2 Operator Qualification a) Has the EDM operator(s) received required training and has training been documented? 10.3 EDM Equipment a) Are all EDM power supply controls that the operator has access to operational/functional? b) Has the EDM machine, dielectric system, and power supply been maintained per the supplier s preventative maintenance plan? c) Have all meters and gages been calibrated, on EDM machines according to the N/A supplier s calibration plan? d) Are conductivity measuring devices for water based dielectric calibrated? N/A e) Are gages that are used for reference only labeled accordingly? N/A f) Has the EDM power supply operation been verified or all power supply meters and gages calibrated per supplier s plan? g) Is the EDM dielectric fluid listed in the workstation instructions, or general EDM instructions, the same fluid used in the EDM machine? h) Is the electrical conductivity of the EDM water dielectric fluid within limits in the N/A workstation instructions or in a supplier controlling document? i) Are any external capacitors or capacitor boxes calibrated and do they have a calibration sticker attached? N/A

13 PRI AC7116/3 Revision A Workstation Instructions a) Are workstation instructions available at the workstation? b) Is the EDM operation being performed on the same type of EDM power supply listed in the workstation c) Are the fixture identification number(s), code(s) or description listed in the workstation instructions the same as that used in the EDM machine? d) Are tools, gages and fixtures that the operator is using listed in the workstation e) For sinker EDM, is the electrode(s) listed in the workstation instructions the same N/A as those used at the EDM machine? f) For wire EDM, is the specific wire type and size listed in the workstation N/A instructions the same as that used at the EDM machine? g) If electrode dressing is done as part of the EDM operation, is the electrode dressing equipment listed in the workstation instructions the same as the equipment used at the EDM workstation? N/A h) Is the operator following the workstation instructions listing the number of cuts per electrode or allowable electrode wear before re-dress or electrode replacement? i) Are all of the controls on the EDM power supply set within limits listed in the workstation instructions or within the part program (including revision level) referenced in the workstation N/A j) Is the EDM machine set to the correct polarity as detailed in the workstation k) Are external capacitors or capacitor boxes set within limits listed in the workstation N/A l) When multiple leads are used are they connected per the workstation N/A m) Is the dielectric flushing method on the machine the same as it is described in the workstation n) Is the operator following the part loading and verification method described in the workstation o) Is the operator following the electrode loading and verification method described in the workstation p) Is the EDM operator machining the correct number or range of parts simultaneously as described in the workstation q) Does the part program name or number on the work instructions match the current program and revision level used? r) Have the EDM workstation instructions been approved according to the supplier s internal procedure? s) Have the EDM workstation instructions been approved by the customer? N/A t) Is the operator following the workstation u) If fixture control is used for part acceptance, has the fixture been calibrated? N/A 10.5 Part Cleaning Do pre and post cleaning methods used conform to the customer requirements? N/A

14 PRI AC7116/3 Revision A Part Inspection a) Are the gage(s) and/or measuring devices used within calibration time limits? b) Are all of the measurements described in the workstation instructions being performed at the required frequency? c) Is the supplier visually inspecting all parts for EDM arcing that includes examination of part electrical contact points, and the EDM machined area? d) Are the gages and/or inspection instruments used to inspect parts the same as those listed in the workstation