The Cornwell 20-pc 1/2" Drive Standard & Deep Metric Impact Socket Set, 6-Point No. TSIM320SS is manufactured in the USA from 100 percent USA-made premium alloy steel. The sockets feature a Torque Dispersing System (TDS) that directs turning force to the flats of the fastener and away from the corners to increase turning power and help reduce rounding. Each socket is cold punched for durability and accurate tolerances and features a black oxide finish for corrosion resistance and bold laser-etched size markings for quick identification. The 20-piece set includes standard and deep sockets in sizes 13mm through 19mm, 21mm, 22mm, and 24mm. The sockets come on modular twist-lock rails with magnetic bases in a multi-row tray for flexible storage and organization.