The N-200A Series from Di Chun Iron Works (Taiwan) is a 3-jaw through-hole power chuck designed for heavy-duty turning operations on large-bore CNC lathes. The chuck body uses SCM440 chromium-molybdenum alloy steel sourced from Japan for models up to 10 inches, providing high tensile strength and wear resistance. For the largest sizes (21 inches and above), FCD600 ductile cast iron is used for vibration damping in heavy-cut applications. The through-hole design enables bar feeding and long shaft work, with the draw nut featuring a quick-replace cover for efficient maintenance.

What are the key construction features?

All sliding surfaces, master jaws, and interior wedge components are hardened and precision-ground. This full-surface hardening — rather than hardening only the jaw guideways — provides consistent wear life across all friction interfaces. The wedge bar actuation converts axial draw-tube force into radial clamping through a mechanical advantage that multiplies the cylinder thrust into high gripping forces. A matching ML-series hydraulic cylinder is specified per chuck size for optimal force transmission.

Typical applications

The N-200A Series is applied in heavy industrial turning: oilfield pipe threading, large shaft machining, railway axle turning, and wind turbine component manufacturing. The combination of high gripping force (over 23,000 kgf on larger models) and large through-bore makes it suitable for workpieces where both clamping security and bar-passage capacity are critical. Hard jaws (HJ series) are specified for roughing operations; soft jaws (HC series) are available for finish-machined surfaces where jaw marking must be avoided.