DIYbanter - View Single Post - Drilling through stainless 3/8" steel bolt

notbob

On 2015-07-13, wrote:

The secret when drilling stainless is NEVER let the bit "skate". Keep
a constant pressure on the bit at all times. MAKE the drill cut. If it
skates and heats, the stainless hardens like glass, and NOTHING will
drill it.

True dat!

By "skate", Clare means "not cutting". IOW, if chips are not coming
off the work, it's "not cutting" and will harden the SS. Make sure
"chips" are being created and the drill bit is not merely spinning in
place. If the chips are dark blue/purple, you are feeding the drill
with too much pressure. Back off until the chips are jes bluish.

nb