b'HOLEMAKINGTooling advances quicken the pace.By Frank BurkeA lthough high-speed machining and holemaking initially were employed largely by defense and aerospace manufacturers work-ing with nonferrous materials, in-creasing demand for higher pro-duction and the use of new alloys and harder metals have resulted in vastly improved high-speed hole-making tools.The Need for SpeedThedefinitionofhigh-speedAllied Machine & Engineeringholemaking varies widely depend- The T-A drill with a polycrystalline diamond insert can provide the hole quality needed to ing on the material, the tool, the ap- produce excellent parts and reduce scrap. Notch Point geometry, a special corner clip and a drill plication and other considerations. point angle help minimize delamination upon exiting the hole.Forgeneralpurposes,Steve Pilger, North American productEngineering Corp. in Dover, Ohio,horsepower and the ability to gen-manager for holemaking at YG-1I would place the threshold aterate torque at higher rpm, he Tool (USA) Co. in Vernon Hills, Illi- 20,000 rpm. Another way to expresssaid. Reserve power is also neces-nois, defines high-speed holemak- it would be three to 10 times fastersary in that a machine operating at ing as having a minimum of 5,000than conventional drilling. 100% will wear out more quickly.rpm spindle speed based on popu- Among the primary consider- Pilger said requirements go far lar diameters of carbide drills. ations for successful holemakingbeyond speed.Martin Hobbs, drilling productare the characteristics of the ma- Machine capability, coolant con-specialist at Sandvik Coromant Co.chine and the fixturing. siderations, including pressure and in Mebane, North Carolina, mea- Stability is paramount, Hobbsvolume, and the need for preci-sures high-speed holemaking insaid. Both the fixture and the ma- sion-ground spindles all come into terms of cubic inches or millimeterschine, as well as the toolholdingplay he said. Its also essential to of material removed per minute. method, have to be capable of re- know the machine spindle runout.Intermsofspindlespeed,sisting the feed forces. Rigid fixturing is likewise neces-saidBillRuegseggerIII,prod- Ruegsegger agrees. sary to prevent vibration and chat-uct manager at Allied Machine &Highspeedsrequirehigherter. This is true even in five-axis 18SEPTEMBER 2022 Holemaking.indd 18 8/16/22 11:49 AM'