Plain Hex Nuts
Plain hex nuts are non-self-locking six-sided nuts used on bolts and machine screws. Because they have no built-in locking feature, they're secured with a separate device such as a check nut, lock washer, cotter pin, or safety wire. Monroe Aerospace stocks AN315 plain hex nuts in right-hand (R) and left-hand (L) threads, AN340 and AN345 hex machine screw nuts in coarse and fine thread, and MS35649 and MS35650 hex machine screw nuts in coarse and fine thread. Cadmium-plated steel and stainless versions are available.
Plain hex nuts need a separate locking device, such as a check nut or lock washer. Our aircraft nut guide covers the options. Shop matching jam nuts and lock washers to complete the assembly.
