Feeds & Speeds
- R.P.M. = (3.8197 / Drill Diameter) x S.F.M.
- S.F.M. = 0.2618 x Drill Diameter x R.P.M.
- I.P.M. = I.P.R. (feed) x R.P.M. (speed)
- Machine Time (Seconds) = (60 x Feed minus Stroke) / I.P.M.
![](http://rockymountaintwist.com/cdn/shop/files/Screenshot_2024-03-26_at_3.01.54_PM.png?v=1711486926&width=1080)
Recommended feeds of Various Diameter Drills
![](http://rockymountaintwist.com/cdn/shop/files/Screenshot_2024-03-26_at_2.57.48_PM.png?v=1711486828&width=1080)
Recommended speeds for standard materials with H.S.S. Drills
![](http://rockymountaintwist.com/cdn/shop/files/Screenshot_2024-03-26_at_2.58.33_PM_38050c00-4189-4741-a741-1253cc0ee121.png?v=1711491815&width=1080)