Thread: Sandvik Coolant Fed Drill Bit Puzzle

Saw this at a second hand tool shop this morning and was intrigued. Can anyone suggest how they created the coolant passage ways inside the spiral flutes? There are two inlet holes at the rear end of the bit.

BT

Bob.

I have it in the back of my mind someplace that they drill straight holes through the shank, then hold both ends, and induction heat them and put the twist in. Then creep grind the flute’s .

Phil.

Googling from Phil's comment, I found this

:: FORECREU ::

Cheers,
Andrew