{"product_id":"luth-ar-carbine-lock-ring-castle-nut","title":"Luth-AR Carbine Lock Ring\/Castle Nut – AR-15\/AR-10 Buffer Tubes","description":"\u003cp\u003eThe Luth-AR Carbine Lock Ring\/Castle Nut secures the buffer tube to the lower receiver and prevents the end plate from rotating on AR-pattern rifles. This is a replacement part for worn, damaged, or lost castle nuts during stock or buffer system installation. A properly torqued castle nut is essential for maintaining buffer tube alignment and preventing receiver extension loosening under recoil.\u003c\/p\u003e\u003cp\u003eManufactured from steel with a phosphate finish for corrosion resistance. Installation requires an AR-15 armorers wrench and staking tool. Torque to 35-40 ft-lbs and stake into the receiver threads after installation to prevent loosening. Compatible with mil-spec carbine buffer tubes.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Type:\u003c\/strong\u003e Castle Nut\/Lock Ring\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible Firearms:\u003c\/strong\u003e AR-15, AR-10, and AR-pattern rifles with mil-spec buffer tubes\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 Phosphate\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstallation:\u003c\/strong\u003e Professional recommended (requires torque wrench, armorers wrench, and staking)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncludes:\u003c\/strong\u003e (1) Castle nut\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Luth-AR","offers":[{"title":"Default Title","offer_id":47938436235519,"sku":"LUTHCS-02","price":4.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0729\/0434\/3807\/files\/1290156.jpg?v=1766515124","url":"https:\/\/doublestackstore.com\/products\/luth-ar-carbine-lock-ring-castle-nut","provider":"Double Stack Store","version":"1.0","type":"link"}