Features: High quality, heavy duty ball bearing design for extended tool life. Made with high manganese steel for long durability. Self-tightening keyless chuck automatically increases clamping force, high reliability and stability. Special quenching treated key parts increases durability. Precision machining and testing. Drill chucks are designed for drilling applications in portable work bench, floor drill press, milling machine, lathe, etc. Specification: Material: manganese steel Arbor: MT2 Clamping Range: 1/32''-5/8'', 1/32''-1/2'' (Optional) Package list: 1 x Drill Chuck 1 x MT2 Arbor Package List 1High quality, heavy duty ball bearing design for extended tool life. 2Made with high manganese steel for long durability. 3Self-tightening keyless chuck automatically increases clamping force, high reliability and stability. 4Special quenching treated key parts increases durability. 5Precision machining and testing.