Bolts

Mil-spec bolts are precision externally-threaded fasteners engineered to defined tensile and shear ratings — not commodity hardware. Head styles follow the application: hexagon head for general airframe assembly, 12-point external-wrenching flange heads where high preload meets tight wrench clearance, and close-tolerance shanks for shear and alignment-critical joints. Many drawings offer drilled heads for safety wire and drilled shanks for cotter-pin retention.

The principal U.S. military bolt families: AN3–AN20 hex bolts (alloy steel, 125 KSI, cadmium plated), MS21250 12-point flange bolts (180 KSI), NAS464 shear bolts, NAS6304 A286 shear bolts for elevated temperatures, NAS6603–6620 close-tolerance bolts (160 KSI), and NAS6204 drilled-shank variants. Materials include 4037, 4130, 4140, 8740, E4340 and 6150 alloy steels, with cadmium plate per QQ-P-416 or black oxide per MIL-DTL-13924.

Every lot ships with a Certificate of Conformance; heat-lot traceable mill material reports are available on request. Made to order, ships in 4 weeks, delivered duty paid — US duties included in our prices, with free express shipping on orders of $300 or more. Sold by the piece (EA), 1-piece minimum.

Now stocking: MS21250 12-point flange bolts — 234 SKUs from $3.74, plain and drilled-head, thirteen diameter groups. Hex-bolt and close-tolerance series are being added continuously. Need AN, NAS or other MS bolts? Send the part number and quantity — we quote within one business day.