The ADVANCED SERIES sockets and bit sockets are made for the most demanding professionals. Crafted from custom forged premium steel, they undergo proprietary heat treatment and are precisely machined to perform in the toughest situations Premium S2 steel forged bits are exceptionally strong and durable. These S2 steel bits withstand high torque and do not twist, protecting both the bit and the fastener. The largest 1/2 in. drive hex bit (9/16 in.) is forged with custom Chrome Vanadium steel, giving the large bit balanced tensile strength for optimal performance Our proprietary advanced heat treatment process further enhanced the S2 and Chrome Vanadium steel alloy to achieve the optimal balance of strength and performance. Every hex bit is made true-to-size for the entire length, letting you use the full length of the bit. All bits have chamfered end to ensure a smooth fit onto fasteners Premium Chrome Vanadium steel sockets plated with our SmartKrome protective plating are durable and corrosion resistant Organized in an impact-resistant tool case, the set includes 13 most frequently used SAE hex bit sockets: 1/4 in. drive: 5/64, 3/32, 1/8, 5/32, 3/16, 7/32, 1/4 in.; 3/8 in. drive: 9/32, 5/16, 3/8 in.; 1/2 in. drive: 7/16, 1/2, 9/16 in