SCOPE AND CLASSES

This specification defines the requirements for alloy steel externally threaded fasteners procured under part numbers listed on drawings which refer to this specification. Typically these fasteners are used for tension, shear, and tensionfatigue applications where 160 KSI Ftu and 95 KSI Fsu is desired with a service temperature capability to 450 °F.

Requirements stipulated 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. NAS6603-6620)

Type II – Tension head (hex, double hex, etc.) without a recess drive, short thread (i.e NAS6203-6220)

100° Full flush head, long or short thread (i.e. NAS1580A)

Pan head, long or short thread (i.e. NAS1578A)

Fillister head, long or short thread (i.e. NAS1121-1128)

Full thread (threaded to the head) (i.e. NAS1801)

Type III – 100° Reduced flush head, long or short thread (i.e. NAS1581)

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

Recommendations for improvements or corrections to this specification should be directed to an NASC representative of a using company or to the Executive Secretary of the National Aerospace Standards Committee.

Specifications listed herein, of the issue in effect on date of inquiry, are a part of this specification to the extent indicated. In the case of conflict, the requirements herein shall take precedence.

Should a using company require qualification testing for any product specifying this document, a report for the specific product and product diameter shall be generated by the product manufacturer from product of sufficient shank and thread length to yield inspection and test data for all requirements in TABLE I including tests categorized as not mandatory. Inspection and test data shall be generated in accordance with the prescribed test methods, utilizing the sampling plan specified for a twenty-five (25) piece manufacturing lot and submitted by the product manufacturer to the product user.

Unless otherwise specified, part inventory manufactured to previous revisions of the applicable drawing or specification may be procured and used until stock is depleted.