Toolholding for rotating round tools—end mills, drills, and taps—continues to evolve with innovative designs aimed at guaranteeing precision, security, and repeatability. As a result, suppliers of toolholding technology have made supporting the precision, security, and repeatability of shrink-fit, mechanical, and hydraulic toolholding the highest priority. You don’t have to look any further than the recent offerings from tooling suppliers to find better ways to improve metal removal rates, part quality, and tool life.
The challenge always is to transmit machining force from the machine’s rotating spindle to a metalcutting tool. Toolholders have a front end to grip the rotating round cutting tool and a back end connection to the machine tool spindle. Back end choices to connect to the machine spindle include CAT (ISO), BT (JIS), HSK (DIN), KM (ISO), and Capto (ISO) standard interfaces and the proprietary BIG PLUS. Each has its particular strengths for milling, turning, and drilling, and each requires precision machining, usually grinding, gaging, and advanced inspection to be manufactured to the required precision specifications.
For front end connection to the cutting tool, there are a number of technologies to choose from that have been developed to meet the challenges of high-speed cutting (HSC), heavy-duty roughing of difficult-to-machine metals like Inconel, and sophisticated toolpath strategies. The main culprit that can lead to catastrophic and costly scrapping of workpiece is tool pullout from the toolholder. One chief remedy that has long been identified as beneficial is high gripping torque. To provide additional security, tooling manufacturers have come up with rather ingenious solutions to guard against the possibility of pullout.