#43 drill size
A #43 drill is 0.0890 in (2.26 mm). It is the standard tap drill for #4-40 UNC; the nearest metric drill is 2.25 mm.
#43 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 |
|---|---|---|---|---|
| 2.25 mm | 0.0886" | −0.011 mm | −0.0004" | Smaller |
| 2.3 mm | 0.0906" | +0.039 mm | +0.0016" | 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 #43 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 #43 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" | 0.0160" | 0.0080" | – |
| M2 bolt | 2 mm | 0.26 mm | 0.13 mm | Close fit (close 2.2, normal 2.4 mm) |
| #2 screw | 0.0860" | 0.0030" | 0.0015" | – |
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 #43 drill?
A #43 drill is 0.0890 in, which is 2.26 mm (2.2606 mm exactly).
What is the metric equivalent of a #43 drill?
The nearest metric drill is 2.25 mm, 0.011 mm smaller. The other close size is 2.3 mm.
What tap uses a #43 drill?
A #43 drill is the standard tap drill for #4-40 UNC (about 71 % thread).
Which fractional drill is closest to #43?
3/32 in (0.0938 in) is the closest, 0.0048 in larger.
What does a #43 drill clear?
It clears a #2 screw with 0.0030" total clearance (0.0015" per side).