This SAE Part Standard covers selected machine screw nuts manufactured in accordance with American Society for Mechanical Engineers (ASME) dimensional standards. This document covers material most often used in ship systems and equipment but its use may be applied wherever fasteners of the covered materials are used. This document permits the fasteners to be identified and ordered by a part or identifying number (PIN) as defined in this document.

The purpose of this document is to assist the designer and other personnel in providing requirements and PINS for the most commonly used machine screw nuts. A PIN is normally required for all military applications and provides a useful means of communicating fastener requirements to suppliers and manufacturers in a very succinct manner.