A #47 drill measures 0.0785 inch (1.994 mm). The closest fractional drill is 5/64" (0.0781") and the closest metric drill is 2.0 mm (0.0787"). It is the standard tap drill for #3-48.
What are the #47 drill equivalents?
| Drill | System | Decimal (in) | mm | Difference (in) |
|---|---|---|---|---|
| #47 | number | 0.0785 | 1.994 | 0 |
| #48 | number | 0.0760 | 1.930 | -0.0025 |
| 5/64" | fraction | 0.0781 | 1.984 | -0.0004 |
| 2.0 mm | metric | 0.0787 | 2.000 | +0.0002 |
| #46 | number | 0.0810 | 2.057 | +0.0025 |
Tap drill for: #3-48.
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 #47 drill run?
| Material | RPM (HSS) | Feed (in/rev) |
|---|---|---|
| 6061-T6 aluminum | 9,732 | 0.0016 |
| 360 free-machining brass | 7,299 | 0.0014 |
| 1018 cold rolled steel | 3,893 | 0.0012 |
| 304 stainless steel | 1,946 | 0.0008 |
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 #47 drill in inches?
0.0785 inch, which is 1.994 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, 2.0 mm is within 0.0002 inch.
What tap uses a #47 drill?
It is the standard 75% thread tap drill for #3-48. Tap drills are chosen to leave about 75% of full thread depth, the balance of strength and tapping torque that published charts use.