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    17 Products

    Mil. Spec. Nylon-Insert Locknuts
    3D CAD models available

    These locknuts are manufactured and tested to strict U.S. military standards for material and construction. The nylon insert grips the screw to prevent loosening from moderate vibration without damaging threads. However, the insert may become brittle if exposed to high temperatures. These locknuts are reusable a handful of times, but the holding power decreases with each use.
    Low-Strength Steel
    Image of Product. Front orientation. Locknuts. Mil. Spec. Nylon-Insert Locknuts.
    Rated Grade 2, Class 6, or lower, these locknuts are about half as strong as medium-strength nuts. Use them with screws that have a similar strength rating to avoid stripping threads during installation.
    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
    Insert
    Max.
    Temp.
    Pkg.
    Qty.
    Pkg.
    Cadmium Yellow-Chromate-Plated Steel
    4-40
    1/4"5/32"MS21044-N04250° F1000000000000000
    6-32
    5/16"3/16"MS21044-N06250° F100000000000000
    8-32
    11/32"9/32"MS21044-N08250° F100000000000000
    10-32
    3/8"9/32"MS21044-N3250° F100000000000000
    1/4"-28
    7/16"23/64"MS21044-N4250° F100000000000000
    5/16"-24
    1/2"23/64"MS21044-N5250° F500000000000000
    3/8"-24
    9/16"15/32"MS21044-N6250° F500000000000000
    1/2"-20
    3/4"19/32"MS21044-N8250° F50000000000000
    5/8"-18
    15/16"3/4"MS21044-N10250° F10000000000000
     
    Corrosion-Resistant Stainless Steel
    Image of Product. Front orientation. Locknuts. Mil. Spec. Nylon-Insert Locknuts.
    18-8 Stainless Steel—The choice for wet and outdoor environments, these locknuts resist rust. However, they won't hold up to the harsh chemicals that 316 stainless steel can.
    Thread
    Size
    Wd.
    Ht.
    Mil. Specs.
    Met
    Insert
    Max.
    Temp.
    Specs.
    Met
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    2-56
    1/4"9/64"MS17830-02C, MS21044C02250° FNASM17830, NASM21044100000000000000
    4-40
    1/4"5/32"MS21044C04250° FNASM210441000000000000000
    6-32
    5/16"3/16"MS21044C06250° FNASM21044100000000000000
    8-32
    11/32"9/32"MS21044C08250° FNASM210441000000000000000
    10-32
    3/8"9/32"MS21044C3250° FNASM210441000000000000000
    1/4"-28
    7/16"23/64"MS21044C4250° FNASM21044500000000000000
    3/8"-24
    9/16"15/32"MS17830-6F, MS21044C6250° FNASM17830, NASM2104410000000000000
    7/16"-20
    11/16"15/32"MS17830-7F, MS21044C7250° FNASM17830, NASM21044100000000000000
     
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