VEVOR 4-Jaw Lathe Chuck, 10 in (250 mm), Lathe Chuck, 0.6-9.84 in (15-250 mm) Clamping Range with T-key Fixing Screws Reversible Jaws, HT300 Cast Iron Material, Internal External for Wood Metal LatheProduct 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 rust resistance, ensuring a long lasting service life Self Centering Function The built in self centering feature allows for hassle free use without repeated calibration. It ensures precise control over