1、WORLDWIDEENGINEERINGSTANDARDSMaterial Specification GMW16343Pre-applied, High-Temperature, Anti-Seize Coating for ThreadedFasteners Copyright 2012 General Motors Company All Rights ReservedOctober 2012 Originating Department: North American Engineering Standards Page 1 of 41 ScopeThis specification
2、describes the performancerequirements for a pre-applied anti-seize coatingon threaded fasteners.1.1 Material Description. Material conforming tothe requirements of this specification can be usedin the application up to 700 C. The pre-appliedanti-seize material is dry to the touch.1.2 Symbols. There
3、are three material codes,depending on the maximum operatingtemperature:Code A: Maximum temperature 350 CCode B: Maximum temperature 550 CCode C: Maximum temperature 700 C1.3 Typical Applications. This material is suitablefor threaded fasteners that require a pre-appliedanti-seize coating to prevent
4、galling:x During assembly due to similar metals and/ormechanical locking.x During disassembly due to thermal effects andoxidation.The material is suitable for applications such asdiesel particle exhaust sensors and oxygensensors. The material is also suitable for fastenersapplied to exhaust manifold
5、s, catalytic converters,and turbo chargers.1.4 Remarks. None.2 ReferencesNote: Only the latest approved standards areapplicable unless otherwise specified.2.1 External Standards/Specifications.ISO 10964 ISO 160472.2 GM Standards/Specifications.GMW3059 GMW148722.3 Additional References.TMC003 Materia
6、l Safety Data Sheet guidancedocuments (available at ).Approved Finishers List (available ).3 Requirements3.1 Coefficient of Friction.3.1.1. After coating, the total friction (Ptot) shall be(0.13 0.03) when tested according to ISO 16047,with the following additional requirements:x For studs and bolts
7、 with non-rotating heads orbolts with effective length (from head to first fullthread) 3 d), or fasteners with special lockingthreads, a surrogate bolt (3.1.2) can be usedfor friction testing. The surrogate bolt must becoated together with the production partsunder the same process.x Uncoated test n
8、ut (or bolt, if testing againstcoated nut) and washer must be cleaned anddegreased ultrasonically within 2 hours oftesting.x After tightening, there shall be a minimum oftwo (2) full threads outside the nut and aminimum of one (1) full thread from themaximum grip gauging length.x Tightening speed sh
9、all be (30 3) RPM.For referee purposes, a Coefficient of Friction Testshall be performed after a minimum of 24 hoursafter coating.3.1.2. For new material approval, process thirty(30) test bolts using production equipment withregular production-loading weights and processparameters. This includes pre
10、-treatment (cleaning),coating, post-treatments, and handling. The testparts are as follows:x Stainless steel test washer: 11612106x Stainless steel test nut: 11612105x Stainless steel test bolt: 11612104The Coefficient of Friction 3 sigma values basedon thirty (30) samples are required to be withins
11、pecification.The Coefficient of Friction Test shall be performedby an ISO 17025 accredited laboratory.Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING
12、STANDARDS GMW16343 Copyright 2012 General Motors Company All Rights ReservedOctober 2012 Page 2 of 43.2 Prevailing-on Torque. Assemble the fastenersand spacer sleeve per ISO 10964 Section 8.3.Assembly torque shall be 0.13 x threaddiameter x 0.9 x bolt-proof load.The maximum prevailing-on torque of a
13、ny onesample shall not exceed 0.0035 x (ThreadDiameter)3 in Nm.Example for M10x1.5 Thread:0.0035 x 103 = 3.5 Nm maximum allowableprevailing-on torque.3.3 High-temperature Cycle. After the prevailing-on torque test (3.2), place the test assemblies in apre-heated air-circulating oven for 48 hours at t
14、hefollowing temperatures:Code A: 350 CCode B: 550 CCode C: 700 CThe assemblies shall be at the specifiedtemperature: (0 + 10) C for 48 hours (tolerance: 10 minutes).After 48 hours, remove the assemblies from theoven and air-cool at room temperature (23 5) Cfor at least 1 hour.After the assemblies ar
15、e at room temperature,repeat the heating and cooling cycle one more timeand test per Breakaway and Prevailing-off TorqueTest (3.5).Note: Do not combine this test with the CyclicCorrosion Test (3.4).3.4 Cyclic Corrosion. After the Prevailing-onTorque Test (3.2), expose the test assemblies perGMW14872
16、, UB, All, 4s, Method 1/2, Exposure Dwith a thermal soak addition (Option 4) for 4 hoursat:Code A: 350 C (tolerance: (0+10) CCode B: 550 C (tolerance: (0+10) CCode C: 700 C (tolerance: (0+10) CTest the assemblies per Breakaway andPrevailing-off Torque Test (3.5).Note: Do not combine this test with t
17、he High-temperature Cycle Test (3.3).3.5 Breakaway and Prevailing-off Torque.Disassemble the fasteners and spacer sleeve andrecord the breakaway and prevailing-off torque perISO 10964 Section 9.The maximum breakaway torque of any onesample shall not exceed the input torque from thePrevailing-on Torq
18、ue Test.The maximum prevailing-off torque of any onesample shall not exceed 0.035 x (ThreadDiameter)2 in Nm.Example for M10x1.5 Thread:0.035 x 102 = 3.5 NmDuring disassembly, fasteners shall show nogalling or cold-welding (seizing).3.6 Shelf Life Test. Condition the coated fastenersfor 26 weeks at (
19、23 5) C and a minimum of 35%humidity. There shall be no change in performanceof coating per 3.1 thru 3.5 after conditioning.3.7 As-received Properties.3.7.1 Once the coating material is approved byGM, the color shall be standard with the supplierunless otherwise specified by the purchaser.3.7.2 The
20、anti-seize coated fasteners shall be dryto the touch and not flake off during handling oruse. Dry to the touch shall be confirmed by layingthirty (30) parts individually on tissue paper for1 hour. There shall be no indication of dampnessor discoloration of the tissue paper.3.7.3 The pre-applied anti
21、-seize coating materialshall not be corrosive to steel, stainless steel,aluminum or copper alloys, nor shall it have adegrading effect on the corrosion resistance of thefinish applied to the fastener.3.8 Thread Fill and Coverage. Due to variationsin the types of anti-seize materials and applicationp
22、rocesses, there will be some variation in theamount of material present around thecircumference of the part and along the coveragearea.The minimum coverage length or area shall bedefined on the part drawing. If not specified on thepart drawing, pre-applied anti-seize coating shallcover the entire th
23、readed area.There shall be no significant gaps in the pre-applied anti-seize coating in the entirecircumference (360 coverage). Slight gaps or “pin-holes” caused by the application/drying processand indentations or touch marks from contact ofparts during shipping and handling are permittedbut shall
24、not affect the performance of the pre-applied anti-seize coating.3.9 Engagement Torque. The pre-applied anti-seize coating shall allow finger-effort starting for360 after first thread engagement of the part.3.10 Auto-feed Systems. This specification doesnot include requirements for compatibility wit
25、hauto-feed assembly equipment. The amount ofanti-seize coating applied to the fastener threadscan affect auto-feed performance. CoatedCopyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from I
26、HS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16343 Copyright 2012 General Motors Company All Rights ReservedOctober 2012 Page 3 of 4fasteners used in normal production should beevaluated for compatibility with auto-feedequipment.3.11 Production Part Approval Process (PPAP)and Applicator Approval Req
27、uirements:x Coefficient of Friction (3.1)x Prevailing-on Torque (3.2)x Breakaway and Prevailing-off Torque (3.5)For PPAP, use the production coated part fortesting unless agreed upon by GM FasteningEngineering.For PPAP, a minimum of ten (10) samples shall beused for each test.3.12 Chemical Approval
28、Requirements:x Coefficient of Friction (3.1)x Prevailing-on Torque (3.2)x High-temperature Cycle (3.3)x Cyclic Corrosion (3.4)x Breakaway And Prevailing-off Torque (3.5)x Shelf Life Test (3.6)x Miscellaneous tests (3.7 thru 3.10) shall bereviewed with the approving engineer.For approval testing, use
29、 stainless steel test bolt11612104 and stainless steel test nut 11612105.The coating shall be applied to the test bolt.A minimum of thirty (30) samples shall be used foreach test.4 Manufacturing ProcessThe GM approved process, including pre-treatment(cleaning), coating, and post-treatment, shall bep
30、erformed by one company in one facility. Theequipment, process controls, chemicals, andlocation used must remain the same for regularproduction. This includes pre-treatment, such ascleaning, and post-treatment. These operationscannot deviate without prior approval by GMMaterials Engineering.For each
31、 production lot of coated parts, theapplicator shall supply a certificate to the customerwith the following information:x This specification number.x Applicator name and address.x Coating system used.x Part number.x Date(s) the parts were coated.x Coefficient of Friction, Prevailing-on Torque,Breaka
32、way and Prevailing-off Torque Testresults at PPAP.x Coefficient of Friction, Prevailing-on Torque,Breakaway and Prevailing-off Torque Testresults as per most recent process control test.The applicator shall keep the certificates for aminimum of five (5) years.5 Rules and Regulations5.1 Legal Regulat
33、ions. All materials must satisfyapplicable laws, rules, regulations andrecommendations valid in the country of usage.5.2 Language. In the event of conflict between theEnglish and domestic language, the Englishlanguage shall take precedence.5.3 Inspection and Rejection. Samples ofcomponents or materi
34、als released to a GMmaterial specification shall be tested for conformitywith the requirements of this material specificationand approved by the responsible Engineeringdepartment prior to commencement of delivery ofbulk supplies.A new approval must be received for any changes,e.g., properties, manuf
35、acturing process, location ofmanufacture, etc. If not otherwise agreed, alltesting and documentation normally required forinitial release must be completed.It is the responsibility of the supplier to inform thecustomer in a timely manner, without solicitation,and to include documentation of all modi
36、fications ofmaterials and/or processes and to apply for a newrelease.If not otherwise agreed, all release tests shall berepeated and documented by the supplier prior tocommencement of delivery of non-conforming bulksupplies. In individual cases, a shorter test can beagreed to between the responsible
37、 Engineeringdepartment and the supplier.5.4 Material Safety Data Sheets/Safety DataSheets (MSDS/SDS). For new productsubmissions, or when a change in chemicalcomposition of an existing product has occurred, acomplete copy of the Material Safety DataSheet/Safety Data Sheet must be submitted incomplia
38、nce with the Globally Harmonized Systemof Classification and Labeling of Chemicals (GHS)requirements or other country-specific MSDS/SDSrequirements. In addition, product MSDS/SDSsubmissions must be in compliance with specificcountry General Motors TMC003 Material SafetyData Sheet/Safety Data Sheet g
39、uidancedocuments where available.Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16343 Copyright 2012 General Motors Company All Rights R
40、eservedOctober 2012 Page 4 of 45.5 All materials supplied to this standard mustcomply with the requirements of GMW3059,Restricted and Reportable Substances forParts.6 Approved SourcesMaterials supplied to this specification must beapproved by General Motors.A list of approved materials can be found
41、in theGM Approved Finishers List. This GM Material Fileis provided to third parties to reduce redundanttesting of materials. If approved material alreadylisted is used, the part supplier can use GMMaterial File reference for Production PartApproval Process (PPAP) material approval. If thedecision is
42、 made to use a not yet approvedmaterial, contact the responsible GM MaterialsEngineer for detail on the approval process. Thematerial approval process must be completed priorto PPAP start date of the part supplied to GeneralMotors.7 Notes7.1 Glossary.Breakaway Torque: The initial torque measured int
43、he “off” direction to decrease the axial load in apre-loaded joint.Prevailing-off Torque: The torque measuredwithin 360 after breakaway torque.Prevailing-on Torque: The highest torque valuemeasured in the “on” direction. The anti-seizecoated thread must be in complete engagementwith the mating threa
44、d.7.2 Acronyms, Abbreviations, and Symbols.GHS Globally Harmonized System ofClassification and Labeling ofChemicalsGSSLT Global Subsystem Leadership TeamMSDS Material Safety Data SheetNm Newton-meterPPAP Product Part Approval ProcessRPM Revolutions Per MinuteSDS Safety Data SheetPtot Coefficient of
45、Total Friction8 Coding SystemThis standard shall be referenced in otherdocuments, drawings, etc., as follows:Coating per GMW16343 Code XWhere “X” = applicable material code9 Release and RevisionsThis standard was originated in January 2010. Itwas first approved by the Finishes & CoatingsGSSLT in Oct
46、ober 2012. It was first published inOctober 2012.Issue PublicationDate Description(Organization)1 OCT 2012 Initial publication.Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
