Thru Holes In U-Drills
Thru Holes In U-Drills
(OP)
Hey All !
So im curious i asked people around the workshop and no one has any idea my question is how do they make the U-Drills and carbine drills with through coolant holes that contour to the shape of the drill ?
So im curious i asked people around the workshop and no one has any idea my question is how do they make the U-Drills and carbine drills with through coolant holes that contour to the shape of the drill ?





RE: Thru Holes In U-Drills
The part I'm guessing about is milling the flutes before twisting and hardening; many twist drills clearly have their flutes ground from the solid after hardening, and it would require just a little extra process control to grind flutes in a blank that had twisted holes inside it but no pre-existing flutes on its exterior.
Mike Halloran
Pembroke Pines, FL, USA
RE: Thru Holes In U-Drills
RE: Thru Holes In U-Drills
Many - most HSS oil hole drills are made from special drill rod that is extruded - forged - with the holes and flutes already in them..