A #52 drill measures 0.0635 inch (1.613 mm). The closest fractional drill is 1/16" (0.0625") and the closest metric drill is 1.6 mm (0.0630").
What are the #52 drill equivalents?
| Drill | System | Decimal (in) | mm | Difference (in) |
|---|---|---|---|---|
| #52 | number | 0.0635 | 1.613 | 0 |
| 1/16" | fraction | 0.0625 | 1.587 | -0.0010 |
| 1.6 mm | metric | 0.0630 | 1.600 | -0.0005 |
Drill sets that include this size
Number and letter sizes come in indexed sets; buy the set rather than single drills.
What speed should a #52 drill run?
| Material | RPM (HSS) | Feed (in/rev) |
|---|---|---|
| 6061-T6 aluminum | 12,031 | 0.0013 |
| 360 free-machining brass | 9,023 | 0.0011 |
| 1018 cold rolled steel | 4,812 | 0.0010 |
| 304 stainless steel | 2,406 | 0.0006 |
Starting points from conservative HSS drilling speeds. Small drills often call for more RPM than a benchtop drill press offers; run at the top speed and feed gently. Use cutting oil in steel and stainless, and clamp the work: never hold it by hand.
Cutting fluid for drilling
Frequently asked questions
What is a #52 drill in inches?
0.0635 inch, which is 1.613 mm. Number drills get smaller as the number rises, so the next number up is a smaller drill. If you do not have this exact size, 1.6 mm is within 0.0005 inch.
What tap uses a #52 drill?
No common UNC or UNF thread uses it as its standard 75% tap drill, but it often serves as an alternative drill for a slightly different percentage of thread, or as a clearance or pilot size. The tap drill chart lists every standard pairing.