Drill geometry allows for continuous support
CTW is unique to Dormer Pramet and currently featured in its new R459 drill for applications of up to 8xD in a wide range of materials. However, the cutting tool company hopes to expand its use to other drilling ranges in the near future. A key feature of the R459 is its versatility in machining a variety of materials. Recent in-house testing conducted by Dormer Pramet using the new drill on aluminium, hardened steel and stainless steel showcased how CTW could withstand differing applications and conditions.
During a test in stainless steel 316L with cutting data of Vc 35 m/min at a feed of 0.1 mm/rev (1,395 rpm at 140 mm/min), the R459 ran for 30 minutes of contact time and showed a small amount of pick-up, with a nice even wear scar across the cutting edges.Similarly, when machining aluminium, the drill was run at Dormer catalogue data Vc 285 m/min (11,340 rpm) at a feed of 0.26 mm/rev (2,950 mm/min). After 30 minutes of contact time, the drill showed minimal wear across cutting edges, with a small amount of pick-up.
In the development of the R459 with CTW, Dormer Pramet performed a range of competitor tests, where the drill continued to perform well against five others.
To ensure fairness against the competition, all the drills were tested in the same conditions. With hole depth set at 40 mm while machining hardened steel (AMG 1.5), speed was 80 m/min at 5,092 rpm, with 0.09 mm/rev feed at 458 mm/min. From those tested, Dormer’s drill and only one other competitor lasted the full 30 minutes, drilling more than 340 holes without any problems. In the same timeframe, another lasted half an hour but offered a poor finish and noisy performance.
From the initial test, the best performing competitor was then selected to compare tool life using the same conditions. The R459 lasted for a further 80 minutes, drilling 900 holes without any problems, while the competitor was badly worn after completing the same operation. The tests showcased that even with the CTW web-thinning feature included, deep-hole drills can perform successfully in a range of material applications. This consistent performance and ultimately a reduction in costs offers a win-win solution.