Description / Abstract: Introduction

Note: Nothing in this standard supercedes applicable laws and regulations.

Note: In the event of conflict between the English and domestic language, the English language shall take precedence.

Purpose. This standard will provide detailed design criteria of threaded, extruded barrels for fastening applications of metric screw threads; M6, M8, M10, and M12 and unified inch screw threads,7/16 in. These barrels may be used in heat treated and non-heat treated steel plates for which the material will be limited. Specific manufacturing requirements will also be outlined. Different types of extruded barrels can be formed in each type of steel. This standard will require a type of base steel, design code designation and thread size after the standard number, see Section 8.

Mission/Theme. This document should be used in two (2) manners:

GM design groups should use this document as design information to choose the best extrusion design for their system and then use the provided dimensioning detail to add to the base part design. This standard should be added to the math or drawing as a controlling specification for the individual extrusions on the base part.

The part supplier should build the part to meet the design and performance requirements contained in this standard.

Classification. This standard will be available to all GM divisions and requesting suppliers.

Extruded. The term extruded is used in metalworking and is defined as; to force, press, or push through a die. Extruded fasteners use a stamping process to develop a drawn barrel to replace the traditional fastener. Parts are made in a progressive die and can be threaded on or off the primary stamping line. Figure 1 shows the basic concept of the fastened joint using an extruded plate. In the case of this standard, all extrusions are made from a base steel plate. The base plate steel is moved and used to form the extruded barrel.

Heat Treatment. Part processing for the two (2) types of materials covered by this standard is very different:

Non-heat treated parts are completed parts after the stamping and threading operations.

Heat treated parts receive oven treating at a prescribed temperature for a prescribed time to obtain the strength characteristics prescribed in the appropriate material specification. This heat treating is how a thinner, smaller heat treated part can perform like a non-heat treated part.

Applicability. Applicable for use on all GM vehicles and Vehicle Partitioning Product Structure (VPPS) levels as appropriate.

Remarks. Not applicable.