carbide tipped bowling ball drill - side and front view
Carbide Tipped Bowling Ball Drills were originally designed to drill out finger holes in bowling balls. They can also be used in many drilling applications using Bakelite composites and other similar non-metallic materials. Not intended for hard steel drilling or precision type work.
Bowling Ball Drills page 119A
All sizes 6-1/4" overall length with 3-7/8" flute length.
SIZE DECIMAL EQUIV.
7/16 .4375
1/2 .5000
9/16 .5625
5/8 .6250
21/32 .6562
11/16 .6875
23/32 .7188
3/4 .7500
SIZE DECIMAL EQUIV.
25/32 .7812
13/16 .8125
27/32 .8438
7/8 .8750
29/32 .9062
15/16 .9375
61/64 .9531
31/32 .9688
SIZE DECIMAL EQUIV.
63/64 .9844
1 1.0000
1-1/64 1.0156
1-1/32 1.0312
1-1/16 1.0625
1-3/32 1.0938
1-1/8 1.1250
1-1/4 1.2500