Pilot hole for a #12 wood screw
Hardwood
5/32"
Softwood
9/64"
Use a standard twist drill of this size for the threaded part of a #12 screw. Oak, maple and other dense woods take the larger bit.
Using a taper-point (countersink) bit set? Those sizes are 7/32" for hardwood and 13/64" for softwood.
#12 wood screw pilot hole sizes
| Screw diameter | 0.216 in 5.49 mm |
|---|---|
| Hardwood, standard bit | 5/32" 0.1562 in |
| Softwood, standard bit | 9/64" 0.1406 in |
| Hardwood, taper-point bit | 7/32" 0.2188 in |
| Softwood, taper-point bit | 13/64" 0.2031 in |
Which size to pick
A pilot hole lets the screw thread bite without splitting the wood. If the screw turns hard or the wood starts to split, go up one bit size. If it spins without holding, go down one.
Test on a scrap piece first. Wood density varies, so the same species can call for a different size.
These sizes are for the threaded section only. The upper board needs a clearance hole the size of the screw's smooth shank.
Tools for this job
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