{"product_id":"fortis-standard-castle-nut","title":"Fortis Manufacturing Standard Castle Nut – AR-15\/AR-10 Compatible","description":"\u003cp\u003eThe Fortis Manufacturing Standard Castle Nut secures the receiver extension (buffer tube) to the lower receiver on AR-15 and AR-10 platform rifles. This mil-spec replacement part maintains proper tension on the buffer tube threads and provides staking points for the end plate, preventing loosening under recoil. Whether you're replacing a worn castle nut or building a new lower receiver, this component ensures reliable operation and proper buffer system function.\u003c\/p\u003e\u003cp\u003eMachined from steel with a manganese phosphate finish for corrosion resistance. Features standard mil-spec dimensions and staking notches. Installation requires an AR-15 armorer's wrench and proper torque (35-40 ft-lbs recommended). Staking the castle nut to the end plate after installation is standard practice to prevent rotation.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Type:\u003c\/strong\u003e Castle Nut\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible Firearms:\u003c\/strong\u003e AR-15, AR-10, and other AR-pattern rifles\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFinish:\u003c\/strong\u003e Manganese Phosphate\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstallation:\u003c\/strong\u003e Requires AR-15 armorer's wrench and torque wrench; staking recommended\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncludes:\u003c\/strong\u003e (1) Castle Nut\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Fortis Manufacturing, Inc.","offers":[{"title":"Default Title","offer_id":47937703837951,"sku":"FORTCN-STAND","price":11.35,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0729\/0434\/3807\/files\/2138946.jpg?v=1766496731","url":"https:\/\/doublestackstore.com\/products\/fortis-standard-castle-nut","provider":"Double Stack Store","version":"1.0","type":"link"}