1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW16804 Joint Acceptance Criteria and Repair Method Self-Piercing and Extruding Screws Copyright 2013 General Motors Company All Rights Reserved December 2013 Page 1 of 4 1 Scope Note: Nothing in this standard supercedes applicable laws and re
2、gulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. This specification provides the acceptance criteria and repair methods for parts that are joined with self-piercing and extruding flow drill screws (FDS). 1.2
3、 Applicability. The criteria established in this standard become mandatory when referenced on a product drawing or Statement of Requirements. Deviation from any acceptance criteria provided in this standard shall be identified on the product drawing or Statement of Requirements. 1.3 Usage. This spec
4、ification is limited to M5 self-piercing and extruding flow drill screws. This specification does not apply to joints using thread cutting fasteners, such as sheet metal screws. 1.4 Clarification. For clarification of this specification or editorial comments, email the GM Weld Council at . 2 Referen
5、ces Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. None 2.2 GM Standards/Specifications. None 2.3 Additional References. GM Global Quality Requirements Manual. 3 Requirements 3.1 General Acceptance Criteria. 3.1.1 Presence.
6、A self-piercing and extruding flow drill screw that is missing or not installed is discrepant. 3.1.2 Fully Driven and Seated. A self-piercing and extruding flow drill screw that is not fully driven with the head of the fastener in contact with the part surface is discrepant (see Figure 1). Copyright
7、 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 GMW16804 Copyright 2013 General Motors Company All Rights Reserved December 2013 Page 2 of 4 Figure 1
8、: Seating 3.2 Visual Acceptance Criteria. 3.2.1 Head Broken Off. A self-piercing and extruding screw whose head is broken off is discrepant. 3.2.2 Cracks. A crack that is fully contained within the extrusion is a condition that does not cause the joint to be discrepant. When visible cracks extend be
9、yond the extrusion to the part surface, the process should be adjusted to the original qualified setup to eliminate the condition. See Figure 2. Figure 2: Cracks 3.3 Measurable Acceptance Criteria. 3.3.1 Location. A self-piercing and extruding screw that is placed outside the location tolerance indi
10、cated on the assembly drawing is discrepant. If no location tolerance is specified, screws located greater than 10 mm from the nominal design location are discrepant. Self-piercing and extruding screws must be contained with all edges of the material being joined. A screw is discrepant if the screw
11、head extends over the edge of the top sheet regardless of location tolerance. See Figure 3. Figure 3: Screw Position Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWI
12、DE ENGINEERING STANDARDS GMW16804 Copyright 2013 General Motors Company All Rights Reserved December 2013 Page 3 of 4 3.3.2 Torque. A self-piercing and extruding screw that does not meet the torque requirements on the Fastener Process Data Sheet or Part Release is discrepant. 3.3.3 Stripped Screws.
13、Stripped screws are discrepant. 3.4 Disposition/Repair Procedure. 3.4.1 Disposition. Product containing self-piercing and extruding flow drill screws is conforming when the number of acceptable screws (not discrepant per the requirements of this standard) meets or exceeds the quantity tolerance as i
14、ndicated on the product drawing or Statement of Requirements. Disposition of product not conforming to this standard shall be handled in accordance with GM approved procedures for handling nonconforming material. 3.4.2 Repair Methods. For standard care fasteners the repair requirement is fully drive
15、n, seated, and not stripped (FDSNS). 3.4.2.1 Missing Fastener. Drill a pilot hole, if necessary, at the design location using the drill size indicated in Table 1 and install a specified repair screw. 3.4.2.2 Repair of Screws with Head Broken Off. When possible, extract remainder of the damaged screw
16、. Drill a pilot hole through all parts as close as possible to the originally documented screw location using the drill size indicated in Table 1 and install the specified repair screw. Table 1: Pilot Drill Sizes Note 1 Fastener Size Repair Screw Size Total Thickness of Parts Being Joined (mm) Pilot
17、 Drill Size (mm) M5 M6 2.5 mm to 3.75 mm No.3 (5.41 mm) M5 M6 3.76 mm to 12.0 mm 5.5 mm M5 M6 12.0 mm No.2 (5.61 mm) Note 1: If product documentation designates a different pilot drill size for the discrepant fastener, use the specifically designated pilot drill. 3.4.2.3 Screws Not Fully Seated. Tig
18、hten screw to achieve a fully driven, seated and not stripped fastener. If the screw strips, see “Stripped Screws”. 3.4.2.4 Under Torque Screws. Tighten screw to achieve a fully driven, seated and not stripped fastener. If the screw strips, see “Stripped Screws”. 3.4.2.5 Stripped Screws. Remove stri
19、pped screw. Enlarge pilot hole using the drill size indicated in Table 1 and install the specified repair screw. 4 Manufacturing Process 4.1 Process Control. The assembly source is responsible for establishing practices and test methods to assure that the criteria of this specification are met, and
20、are consistent with the GM Global Quality Requirements (GQR) Manual (Fastening 09.04, Process Control 08.00, and Process Control Plans Implemented 09.00). Self-piercing and extruding screws shall follow the requirements for standard care fasteners. 5 Notes 5.1 Glossary. Not applicable. 5.2 Acronyms,
21、 Abbreviations, and Symbols. Diameter FDS Self-piercing and Extruding Flow Drill Screws FDSNS Fully Driven, Seated and Not Stripped GQR Global Quality Requirements Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking pe
22、rmitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16804 Copyright 2013 General Motors Company All Rights Reserved December 2013 Page 4 of 4 6 Coding System This standard shall be referenced in other documents, drawings, etc., as follows: GMW16804 7 Release and Revisions This
23、 standard was originated in May 2012. It was first approved by the Global Weld Council in November 2013. It was first published in December 2013. Issue Publication Date Description (Organization) 1 DEC 2013 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-,-,-
