Small tools Introduction  Toolholders for back turning - TKFB insert How to select back turning toolholder hand • Machining near the guide bush is possible Right-hand • Narrow cutting edge width of TKFB12R15005M Guide bush • Optimum for small parts and high precision machining E The workpiece burr does not contact the guide bush. Burrs • Machining with a distance from guide bush • Good chip control due to large space between the guide bush and the tool. Left-hand • Excellent chip control in roughing and finishing (plural passes) • Stable accuracy of external diameter dimension: • When burrs occur, if a left-hand toolholder is used, it is not necessary to return workpiece into guide bush in finishing. Guide bush • Also, left-hand toolholders prevent guide bush wear caused by chip biting. Workpiece movement and tool hand selection - in roughing and finishing Roughing Workpiece position after roughing Finishing Burrs Burrs Right-hand Guide bush Burrs Burrs Left-hand Guide bush * Good dimension accuracy: If a left-hand toolholder is used, burrs on workpiece generated in roughing do not damage the guide bush in finishing. E12