Undercut head to accommodate rubber o-ring
An externally threaded fastener whose threaded portion is of one nominal diameter, no 0 (0.060 in./1.5 mm) or larger, designed to be held or driven with either a wrench or an inserted driver or both (excluding internal socket or internal multiple spline types), in sizes below no. 10 (0.190 in./5 mm). No. 10 and larger sizes must have a head designed for any type inserted driver (excluding internal socket or internal multiple spline types), but may also be designed for external wrenching. A locking feature may be incorporated in the design of the head or threads. Excludes bolt, clevis; bolt, externally relieved body; screw, externally relieved body; and screw, assembled washer. See also, screw, instrument; bolt, machine; bolt, internal wrenching; and screw, cap socket head.
NSN 6105-01-487-2481
NSN 5920-01-425-2336
NSN 6130-01-359-5032
NSN 6150-00-368-4734
NSN 5895-01-656-0139
NSN 5855-01-083-9053
NSN 6620-00-079-0311
NSN 5985-01-606-6059
NSN 6645-01-483-1518
NSN 6220-00-841-1275
NSN 5915-01-351-2348
NSN 5998-00-113-4547