#46 drill size
A #46 drill is 0.0810 in (2.06 mm). It sits between #47 and #45 in the number series; the nearest metric drill is 2.05 mm.
#46 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 |
|---|---|---|---|---|
| 2.05 mm | 0.0807" | −0.007 mm | −0.0003" | Smaller |
| 2.1 mm | 0.0827" | +0.043 mm | +0.0017" | 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 #46 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 |
|---|---|---|---|
| M2.5 × 0.45 | 2.05 mm | 76 % | Soft metals, plastics |
| #3-56 UNF | #45 | 78 % | Soft metals, plastics |
| #3-48 UNC | #47 | 67 % | Good in steel |
Clearance for screws and bolts
Bolts and screws a #46 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 |
|---|---|---|---|---|
| #1 screw | 0.0730" | 0.0080" | 0.0040" | – |
| M2 bolt | 2 mm | 0.06 mm | 0.03 mm | Tighter than close fit (2.2 mm) |
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 #46 drill?
A #46 drill is 0.0810 in, which is 2.06 mm (2.0574 mm exactly).
What is the metric equivalent of a #46 drill?
The nearest metric drill is 2.05 mm, 0.007 mm smaller. The other close size is 2.1 mm.
What thread can I tap with a #46 drill?
It leaves about 76 % thread in M2.5 × 0.45 and 78 % in #3-56 UNF.
Which fractional drill is closest to #46?
5/64 in (0.0781 in) is the closest, 0.0029 in smaller.
What does a #46 drill clear?
It clears a M2 bolt with 0.06 mm total clearance (0.03 mm per side); for metric bolts: tighter than close fit.