13/32" drill bit size
0.4063 in
10.32 mm · fractional drill
| Inches | 0.4063 in |
| Millimetres | 10.32 mm |
| Nearest metric drill | 10.3 mm |
| System | Fractional (64ths) |
What 13/32" means
13/32" is a fractional drill, stepping in 64ths of an inch. Fractional sizes are the coarsest of the three systems, which is why a fractional set alone cannot hit most tapping sizes and why number and letter drills exist at all.
The same hole in the other systems
Three drill systems overlap across this range and a workshop rarely has all three. The nearest bit of each other kind to 13/32":
| System | Nearest size | Difference |
|---|---|---|
| number | #1 — 0.228 in | 0.1783 in smaller |
| letter | Y — 0.404 in | 0.0022 in smaller |
| metric | 10.3 mm | 0.019 mm smaller |
One of those is within three thousandths of an inch, which is inside the tolerance of most hand-held work — substitute it and nobody will know.
What gets drilled at 0.4063 inches
Clearance holes for bolts up to about half an inch, and tapping drills for the larger unified threads. Above a quarter inch a hand drill starts to want two hands and a slower speed, and the bit wants a pilot hole.
Either side of it
| Drill | Inches | Millimetres |
|---|---|---|
| 25/64" | 0.3906 in | 9.92 mm |
| X | 0.397 in | 10.08 mm |
| Y | 0.404 in | 10.26 mm |
| 13/32" | 0.4063 in | 10.32 mm |
| Z | 0.413 in | 10.49 mm |
| 27/64" | 0.4219 in | 10.72 mm |
| 7/16" | 0.4375 in | 11.11 mm |
Frequently asked questions
What size is a 13/32" drill bit?
0.4063 inches, which is 10.32 mm. Fractional drills step in 64ths of an inch, which is the coarsest of the three systems and the one most home sets contain.
What is a 13/32" drill bit in mm?
10.32 mm. A metric index will offer 10.3 mm as the nearest stocked size, which is near enough identical.
Is 13/32" a tapping drill size?
Not for any of the unified threads on this site. It sits between the sizes the standard taps call for, so it is a clearance or pilot drill rather than a tapping one.
What is the next size up from 13/32"?
Z at 0.413 inches — 0.0067 inches larger. Below it is Y at 0.404.
Other sizes
- Z drill bit — 0.413 in, 10.49 mm
- 27/64" drill bit — 0.4219 in, 10.72 mm
- 7/16" drill bit — 0.4375 in, 11.11 mm
- 29/64" drill bit — 0.4531 in, 11.51 mm
- 15/32" drill bit — 0.4688 in, 11.91 mm
- 31/64" drill bit — 0.4844 in, 12.3 mm
- 1/2" drill bit — 0.5 in, 12.7 mm
- 33/64" drill bit — 0.5156 in, 13.1 mm