1. Big-bore 4-jaw independent chucks widely used as workholding devices in oil, gas and petrochemical industrial sectors. They are fitted on the oil country lathes (in pairs on opposite ends of the lathe spindle) or the pipe cutting / welding machines to process the long pipes;
2. Popular sizes are OD / ID 800 / 280 mm, 800 / 320 mm, 800 / 360 mm, 1000 / 280 mm, 1000 / 400 mm, 1000 / 560 mm, 1250 / 560 mm, 1250 / 630 mm, 1400 / 700 mm, 1600 / 820 mm or other sizes specified by customers. Lathe spindle mountings on these chucks are available as short-taper direction mounting types as per A2-15, A2-20, A2-28;
3. Top jaws are reversible to perform either internal gripping or external gripping on the workpiece, and available as one-piece design or two-piece design as per customer requirements. Serrated surfaces of the jaw has a hardness of 53 HRC or so. The bearing surfaces on each top jaw are hardened and precision ground. Casting steel made chuck bodies give higher rigidity and greater wear resistance and thus the chucks can give higher gripping forces;
4. The 4-jaw independent chucks can be used individually on the cutting / welding machines, or be used in pairs on both opposite ends of the spindle on the oil country lathes.