#13 drill size
A #13 drill is 0.1850 in (4.70 mm). It sits between #14 and #12 in the number series; the nearest metric drill is 4.7 mm.
#13 at a glance
Decimal, metric and the nearest sizes in the other series.
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 |
|---|---|---|---|---|
| 4.6 mm | 0.1811" | −0.099 mm | −0.0039" | Smaller |
| 4.7 mm | 0.1850" | +0.001 mm | 0" | 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 #13 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 |
|---|---|---|---|
| #12-28 UNF | #14 | 67 % | Good in steel |
| #12-24 UNC | #16 | 57 % | Hard, tough metals |
Clearance for screws and bolts
Bolts and screws a #13 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 |
|---|---|---|---|---|
| #5 screw | 0.1250" | 0.0600" | 0.0300" | – |
| #6 screw | 0.1380" | 0.0470" | 0.0235" | – |
| M4 bolt | 4 mm | 0.70 mm | 0.35 mm | Normal fit (normal 4.5, loose 4.8 mm) |
| #8 screw | 0.1640" | 0.0210" | 0.0105" | – |
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 #13 drill?
A #13 drill is 0.1850 in, which is 4.70 mm (4.6990 mm exactly).
What is the metric equivalent of a #13 drill?
The nearest metric drill is 4.7 mm, 0.001 mm larger. The other close size is 4.6 mm.
What thread can I tap with a #13 drill?
It leaves about 67 % thread in #12-28 UNF and 57 % in #12-24 UNC.
Which fractional drill is closest to #13?
3/16 in (0.1875 in) is the closest, 0.0025 in larger.
What does a #13 drill clear?
It clears a #8 screw with 0.0210" total clearance (0.0105" per side).