Harlingen 5" 3-Jaw Lathe chuck plain back. 2 Sets of jaws. Body is entirely made of wear-resistant semi-steel No.40/No.45 (ASTM) providing a higher hardness at HB190-220 compared to other brands using HT250 cast iron with hardness of HB180-220. High quality No.35 (ASTM) is used to achieve a higher accuracy, strength and extended tool life. Competitors use HT150 cast iron or engineering plastics as a substitute. Specific machines and fixtures have been adapted to process H-Groove simultaneously so the clamping accuracy is guaranteed. Jaw are made of hardened carbon 1045 (ASTM) steel. The jaws are pressed individually to ensure precise fit, powerful clamping performance and each jaw is interchangeable while maintaining accuracy. The scroll is made of hardened and precision machined 5140 (ASTM) to enhance wear resistance and strength. Scroll face threads are processed with high accuracy CNC machining which inproves self-centering performance. Pinions are made of 20CrMnTi with a quenching procedue to enhance wear-resistance and strength. Each chuck body has its own ID and is 100% inspected with trackable data. Lathe Chuck wrench & 1 set of mounting screws included.