|
|
Ignoramus5102 wrote:
I remember that in Russia, there were special drill bits to start
holes. They had a thick shank and sharp (think 40 degrees) conical
end. So they were very rigid and could start a hole precisely where it
was positioned. No "walking". Then you'd switch to whatever drill bit
was necessary to complete drilling.
It was useful for cases where you could not use a punch.
Are there such things in the US, and if so, what are they called?
i
Center drill:
http://www.lathemaster.com/TN_Center_Drills.jpg
--Winston
|