scope:

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 provides a method for evaluating certain performance characteristics of prevailing torque type nuts.

Foreword. Not applicable.

Applicability. The test consists of one installation and one removal of the nut in a test machine using a constant speed nutrunner. For the test, the nut is assembled on a phosphate and oil coated bolt of a grade or property class corresponding to the nut, and a zinc plated test washer is used as the bearing surface. During the installation and removal, three quantities are measured and recorded electronically: (1) prevailing torque on, (2) torque at specified tension, and (3) prevailing torque off.