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    17 Products

    Mil. Spec. Nylon-Insert Locknuts

    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 steel 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. Spec.
    Insert Max.
    Temp., ° F
    Pkg.
    Qty.
    Pkg.
    Cadmium Yellow-Chromate-Plated Steel
    4-40
    1/4"5/32"MS21044-N042501095154A11000000
    6-32
    5/16"3/16"MS21044-N062501095154A1200000
    8-32
    11/32"9/32"MS21044-N082501095154A1300000
    10-32
    3/8"9/32"MS21044-N32501095154A1400000
    1/4"-28
    7/16"23/64"MS21044-N42501095154A1500000
    5/16"-24
    1/2"23/64"MS21044-N5250595154A1600000
    3/8"-24
    9/16"15/32"MS21044-N6250595154A17000000
    1/2"-20
    3/4"19/32"MS21044-N8250595154A1800000
    5/8"-18
    15/16"3/4"MS21044-N10250195154A1900000
     
    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. Spec.
    Insert Max.
    Temp., ° F
    Specs. Met
    Pkg.
    Qty.
    Pkg.
    18-8 Stainless Steel
    2-56
    1/4"9/64"MS17830-02C, MS21044C02250NASM17830, NASM21044196345A18600000
    4-40
    1/4"5/32"MS21044C04250NASM210441096345A21000000
    6-32
    5/16"3/16"MS21044C06250NASM210441096345A2200000
    8-32
    11/32"9/32"MS21044C08250NASM210441096345A23000000
    10-32
    3/8"9/32"MS21044C3250NASM210441096345A24000000
    1/4"-28
    7/16"23/64"MS21044C4250NASM21044596345A25000000
    3/8"-24
    9/16"15/32"MS17830-6F, MS21044C6250NASM17830, NASM21044196345A3420000
    7/16"-20
    11/16"15/32"MS17830-7F, MS21044C7250NASM17830, NASM21044196345A76500000
     
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