#17 drill size
A #17 drill is 0.1730 in (4.39 mm). It sits between #18 and #16 in the number series; the nearest metric drill is 4.4 mm.
#17 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 |
|---|---|---|---|---|
| 4.3 mm | 0.1693" | −0.094 mm | −0.0037" | Smaller |
| 4.4 mm | 0.1732" | +0.006 mm | +0.0002" | 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 #17 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 |
|---|---|---|---|
| #12-24 UNC | #16 | 79 % | Soft metals, plastics |
| M5 × 0.8 | 4.2 mm | 58 % | Hard, tough metals |
Clearance for screws and bolts
Bolts and screws a #17 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 |
|---|---|---|---|---|
| #4 screw | 0.1120" | 0.0610" | 0.0305" | – |
| #5 screw | 0.1250" | 0.0480" | 0.0240" | – |
| #6 screw | 0.1380" | 0.0350" | 0.0175" | – |
| M4 bolt | 4 mm | 0.39 mm | 0.20 mm | Close fit (close 4.3, normal 4.5 mm) |
| #8 screw | 0.1640" | 0.0090" | 0.0045" | – |
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 #17 drill?
A #17 drill is 0.1730 in, which is 4.39 mm (4.3942 mm exactly).
What is the metric equivalent of a #17 drill?
The nearest metric drill is 4.4 mm, 0.006 mm larger. The other close size is 4.3 mm.
What thread can I tap with a #17 drill?
It leaves about 79 % thread in #12-24 UNC and 58 % in M5 × 0.8.
Which fractional drill is closest to #17?
11/64 in (0.1719 in) is the closest, 0.0011 in smaller.
What does a #17 drill clear?
It clears a #8 screw with 0.0090" total clearance (0.0045" per side).