That's the reason the old-timers got rid of the tip on small centre
drills when they first introduced them to their bench grinder.

"Robert Swinney" wrote in message
...
| One failing with Sherline - if they have any failings at all - might
be the
| maximum speed of the lathe spindle. While centering a piece of
drill rod
| with one of the sub-sized center drills ( about 3 sizes below #1) I
was
| quite perplexed when all of a sudden, it quit cutting and went to
"buzzing".
| Close examination of the work piece revealed the tip of the center
drill
| broken off and deeply imbedded in the, errr, "center" of the aborted
| indentation on the drill rod. All this after prescribed "peck
drilling" of
| the center hole. Problem was, the center drill's tiny tip was so
small as
| to require either super delicate pecking or super fast spindle
speed. Of
| course, I had neither. Carbide to the rescue! The offending HSS
center pip
| was conveniently drilled out with my smallest solid carbide drill
bit, about
| 1/8". Mr. Sherline didn't object in any way as carbide chewed away
the
| imbedded HSS center drill tip. Not going too deep with this rescue
| operation left enough meat to effect proper, and very careful,
center
| drilling of the new "carbidized" spot on work piece. Besides the
sloping
| sides of the rescue hole left a nice oil-retention socket. It
almost looked
| as if it was planned that way.
|
| Bob Swinney
|
|