1、 WORLDWIDE ENGINEERING STANDARDS General Specification GMW15540 Clinch Nut Assembly Performance Criteria Copyright 2013 General Motors Company All Rights Reserved May 2013 Page 1 of 4 1 Introduction Note: Nothing in this standard supercedes applicable laws and regulations. Note: In the event of conf
2、lict between the English and domestic language, the English language shall take precedence. 1.1 Scope. This standard applies to clinch nut assembly performance criteria. The nuts may form their own hole or require a pre-pierced hole. The nuts may have prevailing torque feature. 1.1.1 A self-pierce-a
3、nd-clinch nut is defined as an internally threaded fastener having a material piercing-punch feature along with anti-rotational and retention features such that when pressed against the application sheet or plate material, the nut produces its own hole and engages the application material to becomes
4、 an integral part thereof. 1.1.2 Clinch nut is defined as an internally threaded fastener along with anti-rotational and retention features such that when pressed against the application sheet or plate material with a pre-pierced hole, the nut engages the application material to become an integral p
5、art thereof. 1.2 Mission/Theme. This standard provides acceptance criteria for nuts clinched with or without prevailing torque feature used in automotive products that GM is responsible for establishing or approving the product design. This standard covers only the clinch acceptance criteria. All ot
6、her properties of the nut should be defined in the nut specification. 1.3 Classification. The criteria established in this standard become mandatory when referenced in an assembly or product drawing or math data. Deviation from the criteria provided in this standard must be identified on a drawing o
7、r other product engineering design document. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. None 2.2 GM Standards/Specifications. GMW3059 2.3 Additional References. None. 3 Test Preparation and Evaluation 3.1 Re
8、sources. 3.1.1 Calibration. The test facilities and equipment shall be in good working order and shall have a valid calibration label. 3.1.2 Alternatives. Alternative test facilities and equipment may also be used. However, all measuring variables as specified in this standard shall be determined co
9、rrectly with respect to their physical definition. 3.1.3 Facilities. Not applicable. 3.1.4 Equipment. Not applicable. 3.1.5 Test Vehicle/Test Piece. Either the production part or a test coupon of the same material and thickness could be used for testing. The nut must be assembled using the nut manuf
10、acturer suggested process. 3.1.6 Test Time. Not applicable. 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 GMW15540 Copyright 2013 General
11、Motors Company All Rights Reserved May 2013 Page 2 of 4 3.1.7 Test Required Information. Not applicable. 3.1.8 Personnel/Skills. Not applicable. 3.2 Preparation. Not applicable. 3.3 Conditions. 3.3.1 Environmental Conditions. Not applicable. 3.3.2 Test Conditions. Deviations from the requirements of
12、 this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. 3.4 Instructions. Not applicable. 3.5 Data. See 4.1, Performance Standards. 3.6 Safety. This standard may involve hazardous materials, operations, and equipment. T
13、his standard does not propose to address all the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 3.7 Documentation. Samples of c
14、omponents or material released to this standard shall be tested for conformity with the requirements of this standard and approved by the responsible GM Department prior to the start of delivery of production level components or materials. Any change to the component or material, e.g., design, funct
15、ion, properties, manufacturing process and/or location of manufacture requires a new release of the product. It is the sole responsibility of the supplier to provide the customer, unsolicited, with documentation of any change or modification to the product/process, and to apply for a new release. If
16、 not otherwise agreed to, the entire verification test shall be repeated and documented by the supplier prior to start of delivery of the modified or changed product. In some cases, a shorter test can be agreed to between the responsible GM department and the supplier. 3.7.1 Test Results. See 4.1, P
17、erformance Standards. 4 Requirements and Procedure 4.1 Performance Standards. 4.1.1 Push Out Force. The push out force shall not be less than the value outlined in Table 1. Testing shall be conducted as outlined in 4.2, Test Procedures. 4.1.2 Unsupported Torque Resistance. The torque resistance shal
18、l not be less than the value outlined in Table 1. Testing shall be conducted as outlined in 4.2, Test Procedures. Table 1: Target Performance Values for Push-Out and Unsupported Torque Resistance Thread Size Push-Out (N) Minimum Unsupported Torque Resistance (Nm) Minimum M4.2 900 6 M5 900 9 M6 900 1
19、5 M8 900 35 M10 900 53 7/16 in 900 53 M12 900 78 M14 900 120 M16 900 120 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 GMW15540 Copyright
20、2013 General Motors Company All Rights Reserved May 2013 Page 3 of 4 4.1.3 Usage. Nuts attached by clinching are considered satisfactory when they meet the expected design service loads and satisfy functional performance requirements. The evaluation criteria contained in this document has been estab
21、lished as a basis for the manufacturing acceptance of clinched nuts. Furthermore, nuts identified as discrepant often retain a percentage of their retaining properties and may contribute to the integrity of the product. Application of this standard for other uses, such as post-crash quality assessme
22、nt, may lead to erroneous results or conclusions. 4.1.4 Clarification. For clarification of this standard or editorial comments, contact the GM Fastening Engineering Council. 4.2 Test Procedures. 4.2.1 Push Out Testing. The part with clinch nut assembled shall be supported on a hollow fixture during
23、 push out testing as shown in Figure 1. The assembly must be clamped properly. Adding 2.0 mm to the maximum nut body diameter if the nut is round, or adding 2.0 mm to the across corner width will determine the hollow fixture nominal inside diameter dimension. The push out load shall be applied to a
24、test bolt engaged through the nut. The direction of the push force applied should be opposite to the direction the nut was assembled. The applied load shall be through the center axis of the part. The push out force is defined as the maximum axial force that the staked nut can withstand before separ
25、ating from the assembly. The maximum speed of the testing ram should be 0.5 mm/s. Figure 1: Hollow Fixture 4.2.2 Unsupported Torque Resistance. Torsion resistance testing shall be conducted using a fixture to hold the assembly. Testing shall be performed to determine the maximum torque separation fo
26、rce without any axially applied load. The maximum torque occurs when the nut either completely separates from the test coupon or rotates 90 degrees in the assembly. Torque can be applied directly through a test socket that engages the nut body or indirectly through a test bolt which engages the nut
27、thread Figure 2. Test torque may be applied to the nut assembly in either direction if the nut body is engaged, but only in the clockwise directions if a test bolt is used. The speed at which to apply torque is suggested as a slow hand applied rate, not to apply a shock load to the nut. Copyright Ge
28、neral 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 GMW15540 Copyright 2013 General Motors Company All Rights Reserved May 2013 Page 4 of 4 Figure 2: Torque
29、 Resistance Test 5 Provisions for Shipping Not applicable. 6 Notes 6.1 Glossary. Not applicable. 6.2 Acronyms, Abbreviations, and Symbols. GSSLT Global Subsystem Leadership Team 7 Additional Paragraphs 7.1 All parts or systems supplied to this standard must comply with the requirements of GMW3059, R
30、estricted and Reportable Substances for Parts. 8 Coding System This standard shall be referenced in other documents, drawings, etc., as follows: GMW15540 9 Release and Revisions This standard was originated in January 2007. It was first approved by the Global Fastening GSSLT in August 2008. It was f
31、irst published in August 2008. Issue Publication Date Description (Organization) 1 AUG 2008 Initial publication. 2 MAY 2013 Five year refresh of standard. Updated Table 1 with 4.2, M5, and 7/16 sizes. (Fastening Global Subsystem Leadership Team) Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
