Made from FC25, fine grain cast iron; Trapezoidal-thread lead screw * Less than 0.004" jaw deflection at 2,000 lbs. clamping pressure; Base and bed parallel to 0.001"; Jaw surfaces square to 0.002". * Solid iron construction with stress-relieved design; Replaceable jaw plates * Center of base is open for work holding through vise * Fixed jaw is grooved horizontally and vertically for holding round stock