A bolt-load retention (BLR) test is a practical test to determine the bolt load of a fastener joint with time and at given temperatures. There are three types of BLR tests described in this standard, namely general-purpose test, design-purpose test, and screening material test. A general-purpose BLR test may be used for screening materials, while a design-purpose BLR test is usually used to verify the BLR behavior of a specific joint. The screening material test is an example of the general-purpose test for typical automotive applications.

This standard provides a test method for determining the torque-tension relationship of a fastener finish as applied to a surrogate screw for the purpose of measuring the frictional characteristic of the fastener finish. The results obtained by this test shall be used as a process control attribute of the fastener finish and shall not be utilized for specific applications.

This specification establishes the requirements for the following types of self-locking nuts:

1. a
   Wrenching nuts: that is, hex, double hex, spline drive
2. b
   Anchor nuts: that is, plate nuts, gang channel nuts, shank nuts

The wrenching nuts and shank nuts are made of low alloy steels, and the nut elements of plate and gang channel nuts are made of carbon steels or low alloy steels and having MJ threads to ISO 5855/2. Nuts have 1100 MPa tensile strength class at room temperature. Maximum test temperature of parts at 235 °C.

This SAE Recommended Practice contains dimensions and their tolerances concerning disc wheel to hub or drum interface areas for truck and bus applications. Disc wheels designed only for single wheel applications (not dual wheels) for light trucks and special or less common applications are not covered in this document.