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castle nut

A castellated nut, sometimes referred to as a castle nut, is a nut with slots (notches) cut into one end. The name comes from the nut's resemblance to the crenellated parapet of a medieval castle. Castellated nuts are sometimes referred to incorrectly as castigated nuts.
While castellated nuts are often referred to as slotted nuts, from a technical perspective, slotted nuts differ slightly from castellated nuts. Castellated nuts are formed with a round section at the top where the slots are located. Slotted nuts do not have this rounded modification. The flat sides of slotted nuts extend fully from the top to the bottom of the nut. Both castellated and slotted nuts are designed to use a pin (usually a cotter pin) that fits through the slots and through a hole in the screw to which the nut is attached. This pin prevents the nut from turning and loosening. Compared with slotted nuts, castellated nuts allow the cotter pin to be confined closer to the margins of the nut itself, providing added secureness.
The bolt has one or two holes drilled through its threaded end. The nut is torqued properly and then, if the slot is not aligned with the hole in the fastener, the nut is rotated forward to the nearest slot. The nut is then secured with a split pin/cotter pin, R-clip or safety wire. It is a positive locking device.Castellated nuts are used in low-torque applications, such as holding a wheel bearing in place.

View More On Wikipedia.org
Recent contents
  1. Arsenal13

    FCD forward controls design trigger guard and castle nut

      1. Want to Buy
    • Meridian
    • Idaho
    Looking for forward controls design winter trigger guard in black TFG and a FCD castle nut in black CNF. PayPal ready. Thanks!
  2. aljames

    PWS Receiver End Plate with Ratchet Lock Castle Nut AR-15, LR-308 Steel Black & Magpul ASAP $50 for Both new

      1. For Sale
    • $50
    • Grants Pass
    • Oregon
    I have a couple sling attachment end plates that need a new home. I got these with some other parts and simply don't need them. The PWS comes with a specific castle nut for the ratchet function. ASAP comes with a little wedgie. Neither has any packaging or instructions. Gear shown is...
  3. bbowl

    H2 Buffer, spring, castle nut, buffer plate, detent/spring

      1. For Sale
    • $45
    • Aloha
    • Oregon
    Everything is new, never installed H2 (4.6oz) buffer, carbine spring, milspec plate, castle nut and buffer detent pin+ spring. $40 shipped or picked up in aloha. OR $25 shipped with standard carbine buffer (3oz) instead of H2, everything else the same.
  4. Gunbuggy

    Colt H2 buffer, 6pos. buffer tube, castle nut and end plate.

      1. For Sale
    • $45
    • Vancouver
    • Washington
    As title says. Took this off of my colt 6920 lower and swapped over to a rifle length setup. Doesn't come with the spring. All is in great shape except for the end plate. Looks to be a little rusty or at least dirty. 45 dollars, 50 shipped.
  5. Tatetz05

    AR -15 carbine buffer tube and handguard.

      1. Want to Buy
      2. Want to Trade For
    • Portland
    • Oregon
    ISO 6 position buffer tube with castle nut and latch plate. Also ISO carbine length handguard to replace delta ring plastic guard. Can trade ammo or gear, but have cash.
  6. Zoolander

    WTB: Castle nut and LPK minus FCG and PG

      1. Want to Buy
    • PORTLAND
    • Oregon
    Need the bits from a LPK, already have the FCG and grip
  7. ZA_Survivalist

    BLK Gen1 Shockwave brace

      1. For Sale
      2. For Trade
    • $35
    • Hillsboro
    • Oregon
    I changed out a pistol brace of mine and so thus I have a spare brace on hand. Gen 1 shockwave brace (black) KAK dimpled tube End plate Castle Nut Also comes with a freebie but Im not sure it’ll have much use to you. Endo tactical brace adapter, Ive filed it down and drilled the adapter to...
  8. Greshamreloadr

    Milspec buffer tube and castle nut

      1. Want to Buy
    • Gresham
    • Oregon
    Looking for a black mil spec buffer tube and castle nut. I have the rest of the stuff. I must have misplaced the one I have. So I figured I would check with the board before getting a new one. I am in Gresham and can meet after work. Thanks
  9. Tikkakoski

    Mil-Spec Ar15 Buffer Tube and Castle Nut

      1. Want to Buy
    • Hillsboro
    • Oregon
    Hey Guys, Anyone have a Mil-Spec 6 position buffer tube and castle nut laying around? Or have a line on where to get a cheap one? I need them to put on my charger to adapt it to my SBA3 brace. Let me know :)
  10. OregonSig

    AR buffer, spring, castle nut, and grip

      1. For Sale
    • $30
    • Eugene
    • Oregon
    Selling a lightly used AR mil-spec buffer and spring set-up with a castle nut and latch plate, $20. Magpul MOE black grip, $15. $30 for everything.
  11. RobMa

    - SOLD- Like new PWS ratchet type castle nut and backplate combos

      1. For Sale
    • $20
    • Seattle
    • Washington
    Like new PWS ratchet type castle nut and backplate combos $20.00 per set of two pieces or $55 for all three sets. (One C-nut not pictured) Like new condition Eliminate the need for staking your castle nuts.. I take PayPal friends and family Shipping OK, S/H 2.99 No trade requests please No...
  12. trekkerpaul

    Shockwave KAK brace and tube, forend grip and metal quadrail

      1. For Sale
      2. For Trade
    • $50
    • Canby
    • Oregon
    Shockwave KAK brace blade-1.0 version, unknown forend grip and unknown metal quadrail. All are for trade or sale. SAW style grip has been SOLD Remaining items as a lot, reduced price of 40.00 Will trade for 545 ammo or magazines, 9mm, 223/556 ammo
  13. pnwhunter69

    Geissele super 42 buffer, buffer spring, buffer tube, BCM QD endplate, castle nut

      1. For Sale
    • $110
    • Molalla
    • Oregon
    Geissele super 42 H1 buffer and buffer spring combo with Geissele buffer tube, BCM QD endplate and castle nut. Buffer and spring are new, buffer tube has very light use. $110 for the complete setup, in Molalla, OR or ship for an additional $8.45 priority to anywhere.
  14. RobMa

    New BCM stock, triggerguard and Mod 3 pistol grip (buffer tube,endplate and castle nut included)*

      1. For Sale
    • $75
    • Seattle
    • Washington
    New BCM stock, triggerguard and Mod 3 pistol grip (buffer tube,endplate and castle nut included)* BCM stock BCM trigger guard BCM grip 6 position carbine length buffer tube Castle nut End plate *Sells as a lot I take PayPal Friends and family No trades please No F2F please Shipping ok (buyer...
  15. RobMa

    New BCM stock, triggerguard and Mod 3 pistol grip (buffer tube,endplate and castle nut included)*

      1. For Sale
    • $75
    • Seattle
    • Washington
    New BCM stock, triggerguard and Mod 3 pistol grip (buffer tube,endplate and castle nut included) BCM stock BCM trigger guard BCM grip 6 position carbine length buffer tube Castle nut End plate *Sells as a lot I take PayPal Friends and family No trades please No F2F please Shipping ok (buyer...
  16. Glockmaster650

    New KAK pistol blade w/endplate and castle nut $40

      1. For Sale
      2. For Trade
    • $40
    • Vancouver
    • Washington
    I have a new KAK pistol blade that I installed but has never been used. It comes with an endplate and castlenut. Looking for $40
  17. 22hopper

    basic mil-spec castle nut

      1. Want to Buy
    • Lake Oswego
    • Oregon
    Finishing up a build and realized I used my last castle nut on another rifle. I can order one online for ~$8 shipped but don’t want to wait the 7-10 days for shipping. If you have one local and can help me out please let me know! Thinking $5-$10 for used/new or let me know if you’d rather...
  18. pnwhunter69

    Buffer tube, buffer, spring, end plate, castle nut $50 new

      1. For Sale
    • $50
    • Molalla
    • Oregon
    Buffer tube buffer buffer spring castle nut end plate milspec all new, I ordered several from Brownells but didn’t need this one $50 in Molalla or ship for $5.
  19. matts

    Black KAK brace, tube, buffer, spring, castle nut and end plate

      1. For Sale
    • $61
    • Vancouver
    • Washington
    This model of pistol brace has an nfa approval letter. If any one cares ;)... New brace, new carbine buffer and spring, rest of it is used, tube has a few dings from the brace set screw getting put in slightly off by the previous owner. (Doesn't show after installation) Thanks for looking..... Matt
  20. WTC

    SBA4 with Enhanced Buffer Tube and Castle Nut New

      1. For Sale
    • $90
    • Sierra Vista
    • Other
    Looking to sell this set for $90 shipped. All new. Just going a different way. I have 3 other style braces just didn't quite like this one. Can include new buffer/spring/endplate for $110 Also have a fake can for 1/2-28 $35 shipped
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