Pilot holes for American wood screws

using fractional inch bits

home > tools > fasteners

These dimensions are for standard American wood screws, which are tapered.  They are not suitable for screws which are not tapered, such as dry wall screws. All dimensions are in inches. The shank pilot hole is one which will clear the thickest part of the screw body.

Screw
gage #
Body dia. Shank
pilot hole
Pilot hole
in softwood
Pilot hole
in hardwood
0 0.060 1/16 1/64 1/32
1 0.073 5/64 1/32 1/32
2 0.086 3/32 1/32 3/64
3 0.099 7/64 3/64 1/16
4 0.112 7/64 3/64 1/16
5 0.125 1/8 1/16 5/64
6 0.138 9/64 1/16 5/64
7 0.151 5/32 1/16 3/32
8 0.164 11/64 5/64 3/32
9 0.177 3/16 5/64 7/64
10 0.190 3/16 3/32 7/64
11 0.203 13/64 3/32 1/8
12 0.216 7/32 7/64 1/8
14 0.242 1/4 7/64 9/64
16 0.268 17/64 9/64 5/32
18 0.294 19/64 9/64 3/16
20 0.320 21/64 11/64 13/64
24 0.372 3/8 3/16 7/32

home | tools index | search |  to email Sizes drawing of envelope |  acknowledgements | 
help | privacy | terms of use