1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW14657 Preapplied Adhesive for Threaded Fasteners Copyright 2013 General Motors Company All Rights Reserved July 2013 Page 1 of 8 1 Scope This specification describes the test procedures and performance requirements used to evaluate the locki
2、ng ability of preapplied adhesive coatings on threaded fasteners. 1.1 Material Description. The adhesive is mechanically applied in liquid form to the specified threads on the fastener. After drying, the fastener is clean and dry, and can be handled normally until it is installed. At that time, the
3、adhesive will be activated and undergo curing. The fully cured properties are expected 72 h after installation. Three (3) grades of material are covered by this specification. 1.1.1 Grade A: Regular strength grade for use with fasteners with serviceability requirements with temperatures up to 135 C.
4、 Lower adhesive strength allows for service removal of bolts with less potential for fastener and/or mating thread damage. 1.1.2 Grade B: Higher strength grade with locking/sealing performance up to 135 C. Use of this material is not restricted to larger fastener sizes, but potential service removal
5、 concerns should be considered before use with M6 or smaller fasteners. 1.1.3 Grade C: Higher strength and temperature resistant grade with locking/sealing performance up to 200 C. Use of this material is not restricted to larger fastener sizes, but potential service removal concerns should be consi
6、dered before use with M6 or smaller fasteners. 1.2 Symbols. Not applicable. 1.3 Typical Applications. Threaded fasteners that require a preapplied adhesive for chemical locking and sealing to prevent self-loosening due to shock, vibration, and thermal effects. 1.4 Remarks. The preapplied thread lock
7、ing adhesive compounds are dry to the touch and remain inert on threaded fasteners until they are engaged into the mating threads. The shearing action/forces of assembly activate the adhesive. After proper cure time and temperature, the adhesive hardens to form a chemical bond between the mating thr
8、eads. This bond prevents loosening of fasteners from shock, vibration, and thermal effects. Note: A fastener with preapplied adhesive shall not be reused. 1.4.1 The preapplied adhesive material approved to this specification is designed to perform up to the temperatures stated in 1.1. For severe ser
9、vice conditions, such as higher temperatures, vibration, and environmental conditions, it is recommended that the fastened joint be validated using intended components, preapplied material and process before release. 1.4.2 The performance of the preapplied adhesive material may not perform as well a
10、s expected if coated parts exposed to excessive humidity, oil and dirt. It is recommended that coated parts be handled with care after coating. Similarly, over time, the coating material will degrade from oxidation and other environmental effects. If coated parts are to be stored for more than one (
11、1) year, it is recommended that the appropriate performance test be performed prior to installation. 1.4.3 Not all finishes (coating/plating) are tested to be compatible with all GM approved preapplied adhesive materials. It is recommended that the appropriate performance test be performed to ensure
12、 compatibility. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 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 E
13、NGINEERING STANDARDS GMW14657 Copyright 2013 General Motors Company All Rights Reserved July 2013 Page 2 of 8 2.1 External Standards/Specifications. ASTM F467M ISO 10964 SAE/USCAR-10 2.2 GM Standards/Specifications. 9985809 GMW3044 GMW3221 GMW16551 9986153 GMW3059 GMW3359 9986333 GMW3179 GMW16072 2.
14、3 Additional References. TMC003 Material Safety Data Sheet guidance documents (available at ). 3 Requirements 3.1 Requirements on Test Specimens. Reference GMW3221. 3.1 1 Condition of Parts. 3.1.2 Pre-Coat Condition. Thread surfaces shall be clean, dry, and free of surface contamination just prior t
15、o application of preapplied adhesive coating. 3.1.3 Dry to Touch. The adhesive coated fasteners shall be dry to the touch, yet not flake off during handling or use. Dry to the touch shall be confirmed by laying thirty (30) parts individually on dry tissue paper for 4 h. There shall be no change in a
16、ppearance of the tissue. 3.1.4 Coverage. Unless otherwise specified on the drawing, the thread adhesive shall cover 1.5x bolt diameter, starting at the third (3rd) thread. The first two (2) and last two (2) threads leading and trailing threads, respective, shall be free of adhesive material. See Fig
17、ure 1. Note: Shortened coverage length of adhesive may substantially affect performance. Actual values for nonstandard lengths are to be determined with actual testing of the part. 3.1.5 Thread Fill. Coated threads shall have an average of at least 50% fill for each full thread within the minimum co
18、verage length, with no sags resulting in less than 20% fill. The leading and trailing threads beyond the minimum coverage length may have less than 50% fill. Examination of coated threads shall be by optical comparator or microscope at 10x minimum. 3.2 Test Specimens for Material Qualification. 3.2.
19、1 All fastener test specimens used in one (1) series of tests shall be taken from one (1) fastener and coating/plating lot and shall meet all dimensional requirements after application of coatings/plating. 3.2.2 A minimum of thirty (30) nut/bolt assemblies shall be prepared for each test performed e
20、xcept chemical resistance test. For each chemical resistance immersion condition, five (5) nut/bolt assemblies shall be used. Test samples shall not be reused for multiple tests. 3.2.2.1 Test Bolts. Bolt test samples for initial material qualification shall conform to the requirements of GMW16551 af
21、ter coating/plating. Finish materials and applicators used must be per the respective specifications, including the usage of approved material and applicators. 3.2.2.2 Test Bolt Sizes. M6 1: 6 h, Grade 8.8 M8 1.25: 6 h, Grade 8.8 M10 1.50: 6 h, Grade 10.9 M12 1.75: 6 h, Grade 10.9 3.2.2.3 Test bolt
22、finishes. Zinc phosphate and organic topcoat per GMW3179 Code G. Non-electrolytically applied zinc rich coating per GMW3359. Zinc plating and friction modifying topcoat per GMW3044 8K240/120 Code G. Zinc plating with no topcoat per GMW3044 8K240/120 Code N. Copyright General Motors Company Provided
23、by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14657 Copyright 2013 General Motors Company All Rights Reserved July 2013 Page 3 of 8 3.2.2.4 Apply thread adhesive to the test bol
24、ts per 3.1.1 through 3.1.4. 3.2.2.5 Test Nuts. Steel test nuts shall conform to the nuts described in SAE/USCAR-10. Aluminum test nuts shall be uncoated wrought aluminum alloy per ASTM F467M requirements. General dimensional requirements per GMW16551. All thread tolerances shall be Class 6H. 3.2.2.6
25、 Adhesives shall not be applied to the threads of test nuts. 3.2.3 All test specimens shall be gaged before test to ensure all relevant dimensions are met. This data shall be made available upon request. 3.2.4 Test specimens shall be examined for defects and be removed for the following reasons: Dam
26、aged thread forms, tight or excessively loose fits, sticking, or galling. Rust or visible corrosion. Poor or irregular finish drips or sags. 3.3 Test Procedures. For new material approval testing, use parts and finishes described in 3.2 and Table 1. For Production Parts Approval Process (PPAP), prod
27、uction lot certification, and for referee purposes, use actual production parts. 3.3.1 Prevailing on Torque. Test coated samples per ISO 10964. Assemble coated bolts per Section 8 of ISO 10964, Unseated Assembly. Torque readings shall be measured during assembly for the maximum prevailing on torque.
28、 3.3.2 Breakaway Torque. After tightening per 3.3.1, allow test samples to cure for 72 h at 23 C 2 C and 40% to 50% relative humidity. The fastener shall then be rotated in the off direction at a rate of 10 rpm to 20 rpm with a torque measuring device of suitable capacity and sensitivity, and disass
29、embly for the breakaway torque. Note: Cure time may be reduced per the adhesive suppliers recommendations. 3.3.3 Chemical Resistance Test. Assemble adhesive coated bolts (M10 1.5 only) and steel nuts per 3.2.2.5. After curing, immerse test assemblies in the fluids and temperatures indicated below fo
30、r 168 h. Commercial 5W30 engine oil; 150 C 2 C. DOT3 Brake Fluid (GMW16072); 150 C 2 C. 50%/50% by volume mix of water and 9985809: long life engine coolant; 100 C 2 C. 9986153 or 9986333: Transmission Fluid;150 C 2 C. Commercially available gasoline; 23 C 2 C. Upon removal of the test specimens fro
31、m the test fluid, the bolt-nut assemblies shall be held at 23 C 2 C for a minimum of 1 h. The breakaway torque shall be determined per 3.3.2. The breakaway torque value of each assembly shall conform to the requirements specified in Table 2. Note: This test is only required for initial material appr
32、oval. 3.3.4 Hot Strength. Assemble adhesive coated bolts (M10 1.5 only) and steel nuts per 3.3.1. After curing, place the test assemblies in an air-circulating oven for 2 h at the following temperatures: 135 C for Grade A and B. 200 C for Grade C. After 2 h at temperature, take the assemblies out an
33、d immediately measure breakaway torque at the elevated temperature per 3.3. The breakaway torque value of each assembly shall conform to the requirements specified in Table 2. Note: This test is only required for initial material approval. 3.3.5 Thermal Cycling. Assemble adhesive coated bolts (M10 1
34、.5 only) and aluminum test nuts per 3.3.1. After curing, place specimens in a thermal cycling chamber capable of -30 C to 200 C. Begin cycle at 25 C and ramp at 2 C/minute to 135 C 2 C for Grade A and Grade B and 200 C 2 C for Grade C. Copyright General Motors Company Provided by IHS under license w
35、ith General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14657 Copyright 2013 General Motors Company All Rights Reserved July 2013 Page 4 of 8 Hold at temperature for 1 h. Then ramp down at 2 C/minute to -30 C
36、2 C and hold for 1 h. The cycle shall be repeated to a total of 25 times. After cycling, the breakaway torque shall be tested per 3.3.2. Note: This test is only required for initial material approval. 3.3.6 Heat Age. Assemble and test parts per 3.3.4, except the exposure time is 500 h. Note: This te
37、st is only required for initial material approval. 3.3.7 Shelf Life Test. Store fifty (50) coated test bolts in an open box for six (6) months at 25 C 5 C and then test breakaway torque per 3.3.2. All parts must exhibit the same performance as before the six (6) month storage. Note: This test is onl
38、y required for initial material approval. Table 1: Test/Test Sample Combinations Test Bolts Nut Material Size Finish Prevailing on torque and Breakaway torque All All Steel Chemical resistance M10 All Steel Hot strength M10 All Steel Thermal cycling M10 All Aluminum Heat age M10 All Steel Sealabilit
39、y M10 All Steel Shelf life M10 All Steel 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 GMW14657 Copyright 2013 General Motors Company All
40、Rights Reserved July 2013 Page 5 of 8 Table 2: Prevailing on Torque and Breakaway Torque Requirements Grade A Grade B Grade C Test Fastener Size Minimum (Nm) Maximum (Nm) Minimum (Nm) Maximum (Nm) Minimum (Nm) Maximum (Nm) Prevailing on Torque M6 N/A 0.6 N/A 0.6 N/A 0.6 M8 N/A 1.5 N/A 1.5 N/A 1.5 M1
41、0 N/A 2.0 N/A 2.0 N/A 2.0 M12 N/A 3.5 N/A 3.5 N/A 3.5 M14 N/A 5.5 N/A 5.5 N/A 5.5 M16 N/A 8.0 N/A 8.0 N/A 8.0 Cured Breakaway M6 0.8 8.0 1.5 16.0 1.5 16.0 M8 2.0 18.0 4.0 35.0 4.0 35.0 M10 5.5 33.0 11.0 66.0 11.0 66.0 M12 8.0 55.0 16.0 110.0 16.0 110.0 M14 11.0 90.0 22.0 180.0 22.0 180.0 M16 16.0 15
42、0.0 33.0 300.0 33.0 300.0 Other BreakawayNote 1 5W30 Engine Oil M10 x 1.5 2.8 33.0 5.5 66.0 5.5 66.0 Brake Fluid M10 x 1.5 2.8 33.0 5.5 66.0 5.5 66.0 50/50 Coolant and Water M10 x 1.5 2.8 33.0 5.5 66.0 5.5 66.0 Transmission Fluid M10 x 1.5 2.8 33.0 5.5 66.0 5.5 66.0 Gasoline M10 x 1.5 2.8 33.0 5.5 6
43、6.0 5.5 66.0 Hot Strength M10 x 1.5 2.0 33.0 4.0 66.0 4.0 66.0 Cyclic Age M10 x 1.5 6.0 33.0 12.0 66.0 12.0 66.0 High Temperature Age M10 x 1.5 2.8 33.0 5.5 66.0 5.5 66.0 Note 1: These tests are for Engineering Material Qualification only. Not intended for application specific testing. N/A = Not app
44、licable. Nm = Newton meters. 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 GMW14657 Copyright 2013 General Motors Company All Rights Reser
45、ved July 2013 Page 6 of 8 Figure 1: Thread Coverage Requirements 4 Manufacturing Process 4.1 Cleanliness. The fastener supplier and plating/coating suppliers are responsible for providing parts to adhesive coating supplier that is clean and without debris. Finished parts with preapplied adhesive coa
46、ting shall be stored and transported in clean oil free containers. 4.2 Compatibility with Auto Feeder. This specification does not address compatibility with auto feed assembly equipment. Preapplied coatings may be detrimental to auto feeder performance. Coated parts should be evaluated in productio
47、n auto feed equipment to assess compatibility. 4.3 Friction Control Oils. Certain types of coatings for friction control, such as GMW3179 Code A or G oil, may cause adhesion problems with the thread adhesive. In those cases, the thread adhesive shall be applied before final application of oil. 5 Rul
48、es and Regulations 5.1 Legal Regulations. All materials must satisfy applicable laws, rules, regulations and recommendations valid in the country of usage. 5.2 Language. In the event of conflict between the English and domestic language, the English language shall take precedence. 5.3 Inspection and
49、 Rejection. Samples of components or materials released to a GM material specification shall be tested for conformity with the requirements of this material specification and approved by the responsible Engineering department prior to commencement of delivery of bulk supplies. A new approval must be recei
