For Frozen Screw Removal And Long, Long Life
If none of the common methods for removing a frozen screw work, and drilling is in order, these carbide center drills should be used to center and "start" the hole. With the spindle at fairly high speed, bring the center drill down to the screw head and adjust position until centered in the screw. Apply pressure and cut until center hole is deep enough to allow the proper undersized, regular drill bit to start cutting without catching on the screw head slot. Better for drilling broken taps too, for they will cut center holes in even the hardest ones. And, because of the large body mass of the tool relative to the small drill diameter, it is very sturdy and rigid. Will not flex or walk.
Big Book Catalog, Issue:72, Page:447
SPECS: #1, .125 body/.0468 drill; #2, .187
body/.0781 drill; #3, .250 body/.1093 drill; #4,
.312 body/.1250 drill.