Unistrut P1010EG Electrogalvanized Steel Channel Nut With Spring 1/2 Inch Genuine UNISTRUT Brand Channel Nut With Spring For use with: P1000, P1100, P2000, & P3000 and All 1-5/8" Channels Nut thread size: 1/2"-13 Finish: Electro-Galvanized; ASTM B633, Type III