b'Productive Timesthe late 1960s, which moved onlyAn insert from a TungSix-Drill in one axis and didnt have a recallshows wear after machining a function to put the head back intoreducer part.its previous position after a tool was extracted from a bore. This limita-tion meant that the machine didntof the channel is a slot that know where it left off and thereforedirects coolant toward the increased cycle time to air-cut theinsert and pushes chips length drilled previously. through the flute and out Because of the abusive workof the hole.that we do, he said, the older ma- Geyer conducted a test chines tend to provide us better re- todeterminehowthe sults than newer machines. TungSix-Drillcompared WhileattendingaTungaloywiththedrillthatMet-America Inc. seminar, Geyer be- alTek International used, came interested in the TungSix- as well as a drill from an-Drill from the Arlington Heights,other cutting tool man-Illinois-based toolmaker becauseMetalTek International ufacturer. That third tool of the double-sided insert designbreaker to be optimized for the twofrom a different toolmaker with six cutting edges, which im- pockets to produce the best chips.performed better than the original proves insert strength. Furthermore,Because the cutting speed at thedrill but had to run at about 27 m/the pocket geometry varied be- central pocket approaches zero to- min. (90 sfm). In comparison, the tween the drills central and periph- ward the center axis, the chip for- TungSix-Drill ran at a cutting speed eral pocket. He also was attractedmation is different from the chipsof 52 m/min. (170 sfm) during the by the shape of the coolant chan- produced by the peripheral insert. test. Results showed that the origi-nels, which he said delivered cool- The most important point is thatnal drill was able to run at a cutting ant more effectively to the face ofthe insert corner angle in the centralspeed of 30 m/min. (100 sfm), a feed the insert where its needed. pocket has an obtuse angle design,rate of 25 mm/min. (1 ipm), a spin-Kedar Bhagath, chief technicalwhich strengthens the insert anddle speed of 129 rpm and an opera-officer of Tungaloy America, ex- avoids insert fracture, he said. tion time of 463 seconds per hole. plained that one side of the dou- Bhagath said the drills two cool- In contrast, the TungSix-Drill ran at ble-sided insert is for the peripheralant channels are twisted with thea feed rate of 51 mm/min. (2 ipm), pocket and the other is for the cen- flute shape to allow a larger chipa spindle speed of 220 rpm and an tral pocket, which allows the chip- gullet area. In addition, at the endoperation time of 273 seconds per OIL MIST & SMOKE IN YOUR SHOP?www.mistcollectors.comTel: 1-800-645-4174Low-Cost, Highly Efficient Mist and SmokeCollectors Designed Specifically for theMetalworking Industry78AUGUST 2020 ProTiimes.indd 78 7/17/20 3:52 PM'