Drill 110 copper with HSS at about 90 SFM: 688 RPM for a 1/2 inch drill, 1,376 RPM for 1/4 inch, feeding about 0.0037 in/rev at 1/4 inch.
What RPM and feed for 110 copper?
| Drill | RPM | Feed (in/rev) | Feed (IPM, capped 2500 RPM) |
|---|---|---|---|
| 0.0625" | 5,500 | 0.0009 | 2.34 |
| 0.125" | 2,750 | 0.0019 | 4.69 |
| 0.1875" | 1,833 | 0.0028 | 5.16 |
| 0.25" | 1,375 | 0.0037 | 5.16 |
| 0.3125" | 1,100 | 0.0047 | 5.16 |
| 0.375" | 917 | 0.0056 | 5.16 |
| 0.5" | 688 | 0.0075 | 5.16 |
| 0.625" | 550 | 0.0094 | 5.16 |
| 0.75" | 458 | 0.0112 | 5.16 |
Tools for cutting 110 copper
How does 110 copper machine?
Pure copper is soft and gummy, which is harder to machine well than its softness suggests. Very sharp, high positive rake tools, a generous flow of cutting fluid and a light finishing pass are what get a clean surface.
Why a HSS twist drill?
Twist drill speeds are set lower than turning speeds because the cutting edge is buried in the hole with no escape for heat. Peck deep holes (clear chips every one to two diameters), and use cutting oil in everything except cast iron, brass and plastics.
Adjust speeds with the RPM calculator and milling feeds with the feed rate calculator. The cutting speed chart compares every material.
Frequently asked questions
What SFM for 110 copper?
A starting surface speed of 100 SFM with HSS and 350 SFM with carbide, and 90 SFM for HSS drills. These are conservative for hobby machines; raise them in steps if the chips come off clean and the tool stays cool. 110 copper rates poor (gummy) for machinability.
What happens if my machine cannot reach the RPM?
Run at your top speed. Running below the ideal surface speed only makes the job slower; it does not damage the tool. For milling and drilling, keep the chip load per tooth or feed per revolution the same so the edge keeps cutting instead of rubbing, which lowers the feed in inches per minute in proportion.
Other tools in 110 copper
Other materials with a HSS drill
- 6061-T6 aluminum
- 7075-T6 aluminum
- 360 free-machining brass
- 932 bearing bronze
- 12L14 leaded steel
- 1018 cold rolled steel
- 1045 medium carbon steel
- 4140 alloy steel (annealed)
- All