Tap and Drill Sizes
Tap Thread Drill Drill Drill   Tap Thread Drill Drill Drill
Soft Hard Ave.   Soft Hard Ave.
 
0 ~ 80 3/64" #55   3/8" ~ 32 11/32" T
1 ~ 72 #53 #52 1/16"   3/8" ~ 24 Q S 11/32"
1 ~ 64 #53 1/16"   3/8" ~ 16 5/16" Q
2 ~ 64 #50 #48 5/64"   7/16" ~ 28 Y Z
2 ~ 56 #50 #49 5/64"   7/16" ~ 20 25/64" 13/32"
3 ~ 56 #45 #43 3/32"   7/16" ~ 14 U 25/64"
3 ~ 48 #47 #44 3/32"   1/2" ~ 20 29/64" 15/32"
4 ~ 48 #42 #40 3/32"   1/2" ~ 13 27/64" 29/64"
4 ~ 40 #43 #41 3/32"   9/16" ~ 18 33/64" 17/32"
5 ~ 40 #38 7/64"   9/16" ~ 12 32/64" 33/64"
5 ~ 44 #37 #35 7/64"   5/8" ~ 18 37/64" 37/64"
6 ~ 40 #33 #31 1/8"   5/8" ~ 11 17/32" 17/32"
6 ~ 32 #36 #32 7/64"   3/4" ~ 16 11/16"
8 ~ 36 #29 #26 9/64"   3/4" ~ 10 21/32"
8 ~ 32 #29 #27 9/64"   7/8" ~ 14 13/16"
10 ~ 32 #21 #18 11/64"   7/8" ~ 9 49/64"
10 ~ 24 #25 #20 5/32"   1" ~ 12 29/32"
1/4" ~ 32 7/32" #1   1" ~ 8 7/8"
1/4" ~ 28 #3 #1 7/32"   1‑1/4" ~ 12 1‑11/64"
1/4" ~ 20 #7 7/32"   1‑1/4" ~ 7 1‑7/64"
5/16" ~ 32 9/32" L   1‑1/2" ~ 6 1‑21/64"
5/16" ~ 24 I 9-32"  
5/16" ~ 18 F J 17/64"   This is only a guide, Consider Material & Thickness