NAS 509 Rev. 8

This specification defines the requirements for corrosion resistant steel externally threaded fastners procured under part numbers listed on drawings which refer to this specification. Typically, these fastners are used for tension, shear, and tension-fatigue applications where 160 KSI Ftu and 95 KSI Fsu is desired with a service temperature capability to 1000°F unplated.
Requirements stipluted in purchase contracts, purchase orders, part standards and/or part drawings shall take precedence over requirements stated herein. Receiving contractors may reject any lot which does not conform.
The specification includes mechanical property requirements for three classes of fasteners, Types I, II, and III.

• Type I - Tension head (hex, double hex, etc.) without a recess drive, long thread (i.e. NAS6703-6720)
• Type II - Tension head (hex, double hex, etc.) without a recess drive, short thread (i.e. NAS203-6220) 100° Full flush head, long or short thread (i.e. NAS1580C) Pan head, long or short thread (i.e. NAS1578C) Fillister head, long or short thread (i.e. NAS1121E-1128E) Full thread (threaded to the head) (i.e. NAS1802)
• Type III - 100° Reduced flush head, long or short thread (i.e. NAS1581C)

Workmanship of fasteners shall be in conformance with aircraft fastener manufacturing processes.

Details

Edition:

Rev. 8

Published:

10/31/2014

Number of Pages:

4