Mil. Spec. Flex-Top Locknuts for Heavy Vibration![For technical drawings and 3-D models, click on a part number. 3D CAD models available](data:image/svg+xml;base64,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)
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These locknuts are manufactured and tested to strict U.S. military standards for material and construction. The top section expands to grip the screw on all sides for a stronger hold than both nylon-insert and distorted-thread locknuts. As a result, they're suitable for use in equipment with constant, vigorous vibration, such as engines. These locknuts are reusable a handful of times, but the holding power decreases with each use.
Steel
These locknuts have equivalent strength to Grade 8 and Class 10 steel nuts. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.
Cadmium Yellow-Chromate-Plated Steel—These locknuts have good lubricity to thread on smoothly and ease installation. The plating also creates a barrier against rust that's comparable to zinc yellow-chromate plating.
Thread Size | Wd. | Ht. | Mil. Specs. Met | Pkg. Qty. | Pkg. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Cadmium Yellow-Chromate-Plated Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
4-40 | 1/4" | 5/32" | MS21045-04 | 5 | 000000000 | 000000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
6-32 | 5/16" | 3/16" | MS21045-06 | 5 | 000000000 | 0000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
8-32 | 11/32" | 1/4" | MS21045-08 | 5 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
10-32 | 3/8" | 1/4" | MS21045-3 | 5 | 000000000 | 0000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1/4"-28 | 7/16" | 5/16" | MS21045-4 | 5 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/16"-24 | 1/2" | 23/64" | MS21045-5 | 5 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
3/8"-24 | 9/16" | 15/32" | MS21045-6 | 5 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
7/16"-20 | 11/16" | 15/32" | MS21045-7 | 1 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1/2"-20 | 3/4" | 39/64" | MS21045-8 | 1 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
9/16"-18 | 7/8" | 11/16" | MS21045-9 | 1 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
5/8"-18 | 15/16" | 49/64" | MS21045-10 | 1 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
3/4"-16 | 1 1/16" | 57/64" | MS21045-12 | 1 | 000000000 | 00000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||