The third way:

Three-claw chuck, Oil-Supply end face sealing and central support is used for clamping; Suitable for holing on workpiece of bigger end surface runout; Oil-supply can only be used for drilling.

Diagram of Boring Process

Self-expanding Skiving and Tumbling combined tool is applicable to volume production of both refine machined high-accuracy cold-drawn tube and other roughly machined steel tube. When diameter allowance is 1mm, Feed Rate can reach 500mm~1250mm per minute, with roundness of 0.01mm, roughness of no more than Ra0.04μm (machining of Ф160mm as example). The core rod inside the boring bar can make scarping knife and rolling column retreat automatically with the help of hydraulic control, to increase efficiency largely without sacrificing the stability of Holing Process. These cutting tools can handle upto Ф400mm, applicable to our ZSK all automatic digital control deep-hole drilling machine, capable of completely replacing the imported.