6-Inch 3-Jaw Lathe Chuck with Backing Plate Our lathe chuck with backing plate achieves faster, steadier machine connection. Built from premium HT300 cast iron, jaw hardness ≥53 HRC for exceptional durability. The self-centering design ensures high-precision clamping ranging from 0.12 in to 5.71 in with 1.77 in I.D and 6 in O.D. Outstanding Hardness Self-Centering Function Hassle-Free Operation Ideal for Most Lathes 6-Inch 3-Jaw Lathe Chuck with Backing Plate Our lathe chuck with backing plate achieves faster, steadier machine connection. Built from premium HT300 cast iron, jaw hardness ≥53 HRC for exceptional durability. The self-centering design ensures high-precision clamping ranging from 0.12 in to 5.71 in with 1.77 in I.D and 6 in O.D. Key Features Outstanding Hardness: Crafted from premium HT300 cast iron, this lathe chuck features jaws with a hardness of ≥53 HRC and a scroll plate hardness of ≥45 HRC. Quench-hardened for enhanced durability, it ensures excellent hardness and