Heat-treated chrome-vanadium alloy steel forged body for long service life. The surface is polished and electroplated with nickel-chromium for hardness and corrosion resistance. Wear-resistant, oil-resistant, water-resistant, not easy to prevent rust. Smoothly rotated 180 degrees, the box end holds any angle for fasteners to slide. The 12-point box end provides a firm grip, no rounding required for tightening or loosening the bolt and no slippage even under high torque when closed. To prevent rounding, it touches and applies force to the flat sides of the fastener head, not the corners. 72 - Tooth mechanism allows you to work in tight spaces with as little as 5 degrees of ratcheting motion. The open end is angled 15 degrees so the key can be flipped over every turn to engage in tight spaces with twice the tightening frequency. It is used to fasten or disassemble hexagon head bolts or nuts; it is widely used in maintenance, machinery, electric power, household, mining and other industries.