#49 drill size
A #49 drill is 0.0730 in (1.85 mm). It sits between #50 and #48 in the number series; the nearest metric drill is 1.85 mm.
#49 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 |
|---|---|---|---|---|
| 1.85 mm | 0.0728" | −0.004 mm | −0.0002" | Smaller |
| 1.9 mm | 0.0748" | +0.046 mm | +0.0018" | 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 #49 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).
Clearance for screws and bolts
Bolts and screws a #49 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 |
|---|---|---|---|---|
| M1.6 bolt | 1.6 mm | 0.25 mm | 0.13 mm | Normal fit (normal 1.8, loose 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 #49 drill?
A #49 drill is 0.0730 in, which is 1.85 mm (1.8542 mm exactly).
What is the metric equivalent of a #49 drill?
The nearest metric drill is 1.85 mm, 0.004 mm smaller. The other close size is 1.9 mm.
What thread can I tap with a #49 drill?
It leaves about 64 % thread in #2-64 UNF and 56 % in #2-56 UNC.
Which fractional drill is closest to #49?
5/64 in (0.0781 in) is the closest, 0.0051 in larger.
What does a #49 drill clear?
It clears a M1.6 bolt with 0.25 mm total clearance (0.13 mm per side); for metric bolts: normal fit.