WORKPRO 55-piece 1/2 Drive Impact Socket Set SAE and Metric Sockets Cr-V Steel. WORKPRO 1/2 Drive Impact Socket Set with Extension Bars, Premium Cr-V Steel, Complete 55-Piece, SAE and Metric Sockets with Enhanced Storage Case. Made of Cr-V steel (50BV30), the surface is heat treated with black phosphate finish to resist corrosion, rust and wear. […]