#25 drill size
A #25 drill is 0.1495 in (3.80 mm). It is the standard tap drill for #10-24 UNC; the nearest metric drill is 3.8 mm.
#25 at a glance
Decimal, metric and the nearest sizes in the other series.
- Decimal inch
- 0.1495"
- Millimetres
- 3.80 mm 3.7973
- Nearest metric drill
- 3.8 mm +0.003 mm
- Nearest fractional
- 5/32" 0.1562", +0.0068"
- Hole area
- 0.0176 in² 11.33 mm²
- Tap drill for
- #10-24 UNC
Nearest metric drills
Metric drills step by 0.05 mm below 3 mm and by 0.1 mm from 3 mm. Difference is metric minus inch size.
| Metric drill | Inch | Difference | In inches | Hole |
|---|---|---|---|---|
| 3.7 mm | 0.1457" | −0.097 mm | −0.0038" | Smaller |
| 3.8 mm | 0.1496" | +0.003 mm | +0.0001" | Larger |
Nearby inch drills
The next size down and up in each inch series, so you can pick a substitute from the drawer.
Threads a #25 drill can tap
Threads from the tap tables on this site that this drill can tap, with the thread percentage it leaves (55–85 % shown).
| Thread | Standard drill | Thread with this drill | Suits |
|---|---|---|---|
| #10-24 UNC | #25 | 75 % | Standard drill |
Clearance for screws and bolts
Bolts and screws a #25 hole clears, with the diametral clearance and the gap each side. Metric sizes are compared with ISO 273.
| Fastener | Diameter | Clearance | Per side | ISO 273, metric only |
|---|---|---|---|---|
| #3 screw | 0.0990" | 0.0505" | 0.0252" | – |
| #4 screw | 0.1120" | 0.0375" | 0.0187" | – |
| #5 screw | 0.1250" | 0.0245" | 0.0122" | – |
| M3.5 bolt | 3.5 mm | 0.30 mm | 0.15 mm | Close fit (close 3.7, normal 3.9 mm) |
| #6 screw | 0.1380" | 0.0115" | 0.0057" | – |
Inch clearance is the drill size minus the basic major diameter. A drilled hole usually cuts slightly oversize.
Number drill index
Every size in the series, holes drawn to scale.
Common questions
What size is a #25 drill?
A #25 drill is 0.1495 in, which is 3.80 mm (3.7973 mm exactly).
What is the metric equivalent of a #25 drill?
The nearest metric drill is 3.8 mm, 0.003 mm larger. The other close size is 3.7 mm.
What tap uses a #25 drill?
A #25 drill is the standard tap drill for #10-24 UNC (about 75 % thread).
Which fractional drill is closest to #25?
5/32 in (0.1562 in) is the closest, 0.0068 in larger.
What does a #25 drill clear?
It clears a #6 screw with 0.0115" total clearance (0.0057" per side).