Browse Prior Art Database

Method of Making Ultra Small Punches and Drill Blanks

IP.com Disclosure Number: IPCOM000122309D
Original Publication Date: 1991-Nov-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 1 page(s) / 38K

Publishing Venue

IBM

Related People

Frankeny, JA: AUTHOR

Abstract

Disclosed is a method of making ultra small punches and drills. Generally these are smaller than 127 micron diameter. A drill is just a punch with flues cut in it and a tapered end.

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Method of Making Ultra Small Punches and Drill Blanks

      Disclosed is a method of making ultra small punches and drills.
Generally these are smaller than 127 micron diameter.  A drill is
just a punch with flues cut in it and a tapered end.

      The present method of making these punches/drills uses cemented
tungsten carbide (TC) where molybdenum is the cement holding the TC
particles together.  There is a lower limit to the average particle
size of the TC which is usually 1 to 2 microns.  This is too large
for good sharp edges and high strength of the punch/drill after
grinding.

      This disclosure explains how to improve the grain size and
strength of the punch/drills.  It consists of three steps:
1.  Make a mandrel of cemented TC as shown in Figure 1, item 1, of
the appropriate size.
2.  Chemical vapor deposit (CVD), in large batches, TC on the mandrel
end as shown in Figure 2, item 2.
3.  Grind the ultra small end of the punch/drill leaving item 3 in
Figure 3.

      The CVD TC has a grain size of less than .25 micron and a
strength 20 to 30% greater than the cemented TC.  Thus, this method
should produce a superior punch/drill that is higher quality and
smaller diameter.

      Disclosed anonymously.