Achieve sub-micron concentric precision when machining your soft top jaws with industrial-grade Jaw Cutting Attachments (chuck boring fixtures). Engineered to preload lathe chuck jaws under actual mechanical clamping pressure, these adjustable ring fixtures simulate true operating conditions during boring or step-turning configurations. Preloading the chuck segments effectively eliminates internal scroll clearance and jaw lift, ensuring that once the soft jaws are bored to the workpiece diameter, they deliver flawless surface contact, maximum holding torque, and absolute rotational tracking accuracy.