The Sons of Liberty Gun Works Castle Nut is precision-engineered from 17-4 stainless steel with nitride treatment for superior durability and corrosion resistance in your AR-15 build.Sons of Liberty Gun Works Castle Nut17-4 stainless steel construction for maximum strengthNitride treated finish for enhanced corrosion resistance6 deep staking notches for secure installationExtended length design3A threads for mil-spec compatibilityPerfect for your next build competition rifle or defensive firearm this castle nut ensures reliable buffer tube retention with premium materials and precision manufacturing that meets mil-spec requirements.