Purpose. This specification establishes the requirements for procurements of taper shank threaded fasteners. These taper shank fasteners are products of licensed manufacturers. Classification. The fasteners covered by this specification shall be the type@ size and material designated by the part number specified on the applicable NAS standard. Type I ?C 100? Countersunk Head Pin (NAS1724@ NAS1725) Type II ?C Protruding Head Pin (NAS1728@ NAS1729) Unless otherwise specified@ part inventory manufactured to previous revisions of the applicable standard or drawing and this specification may be procured and used until stock is depleted.