13 Piece Hex Key Wrench Set Hardened and tempered carbon steel for strength and durability. Black oxide finish to resist rust. Set includes: 0.050mm, 1/16″, 5/64″, 3/32″, 7/64″, 1/8″, 9/64″, 5/32″, 3/16″, 7/32″, 1/4″, 5/16″, and 3/8″ fractional and metric hex keys.