CASTLE NUT FOR AR-15 BUFFER TUBE. Home» FIREARM PARTS, MAGAZINES & CLEANING SUPPLIES» FIREARM FURNITURE, PARTS & ACCESSORIES Enlarge Product ID ATIA.5.10.1020CASTLE NUT FOR AR-15 BUFFER TUBE.Manufacturer ASSORTED758152900067Date Added11th November 2025List Price: $10.47Price: $9.95 AR-15 BUFFER TUBE CASTLE NUT. A castle nut is a type of nut with slots, or notches, cut into one end that resembles the battlements of a castle. It is used in low-torque applications. This prevents the nut from loosening due to vibration or movement, and common use include securing components on firearms. Common applications: Firearm components, such as the buffer tube on an AR-15 and other low-torque assemblies that experience vibration. How it works: Tightening: The castle nut is tightened onto a bolt or buffer Tube. Safety: It is crucial for safety in applications where a nut failure could cause a hazard. Reusability: The nut itself can be reused. Add to cart« Previous | Next »AR15 WEAPON PARTS, AR-15 BUFFER TUBE, CASTLE NUTTweetProduct ReviewsNo Reviews For This Product.Click to review this product RELATED Products AR15 BOLT CARRIER ASSEMBLY - 5.56 / .223Price: $213.07AR15 .223, 5.56, .300 Blackout - Complete Bolt Carrier GroupPrice: $105.95AR15 Buffer End Plate Dual Oval Loop w/ QD Push Button, Sling Swivel AdapterPrice: $19.99