Product Description The Sons of Liberty Gun Works Castle Nut is a precision-machined AR-15 lower parts component originally designed for the SOLGW MK1 platform. Crafted from 17-4 Stainless Steel and treated with a nitride finish for maximum corrosion resistance, this castle nut raises the bar beyond standard mil-spec offerings. The face is ground flat for optimal surface contact with an end plate, while 6 deep staking recesses deliver exceptional material displacement and holding force. The rear is beveled between drive notches for added comfort during installation and operation. Machined to Class 3B thread specifications for rock-solid thread engagement and security, this nut also features an extended length beyond typical mil-spec dimensions, adding material strength at the critical junction of the lower receiver and receiver extension (buffer tube). Compatible with Intermediate/A5 length extensions only. Product Highlights 17-4 Stainless Steel Construction: Provides superior strength and durability over standard carbon steel castle nuts. Nitride Treated Finish: Delivers maximum corrosion resistance for long-lasting performance in demanding environments. Class 3B Threads: Ensures maximum thread engagement and rock-solid security when installed on your lower receiver. 6 Deep Staking Notches: Allows for greater material displacement and significantly more holding force than standard mil-spec designs. Extended Length Design: Adds material strength at the lower receiver and buffer tube junction; compatible with Intermediate/A5 length extensions only. Specs Brand: Sons of Liberty Gun Works Material: 17-4 Stainless Steel Finish: Nitride Treated Thread Specification: Class 3B Staking Notches: 6 Deep Staking Recesses Length: Extended (beyond standard mil-spec) Compatibility: Intermediate/A5 Length Extensions Only MPN: SOLGW-CASTLENUT UPC: 657628674443 Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product&';s manufacturer. ]]>