Drill 1045 medium carbon steel with HSS at about 70 SFM: 535 RPM for a 1/2 inch drill, 1,070 RPM for 1/4 inch, feeding about 0.0032 in/rev at 1/4 inch.
What RPM and feed for 1045 medium carbon steel?
| Drill | RPM | Feed (in/rev) | Feed (IPM, capped 2500 RPM) |
|---|---|---|---|
| 0.0625" | 4,278 | 0.0008 | 2.03 |
| 0.125" | 2,139 | 0.0016 | 3.48 |
| 0.1875" | 1,426 | 0.0024 | 3.48 |
| 0.25" | 1,070 | 0.0032 | 3.48 |
| 0.3125" | 856 | 0.0041 | 3.48 |
| 0.375" | 713 | 0.0049 | 3.48 |
| 0.5" | 535 | 0.0065 | 3.48 |
| 0.625" | 428 | 0.0081 | 3.48 |
| 0.75" | 357 | 0.0097 | 3.48 |
Tools for cutting 1045 medium carbon steel
How does 1045 medium carbon steel machine?
1045 is a stronger, harder medium carbon steel used for shafts and pins. It machines to a better finish than 1018 but needs slower speeds and a rigid setup; it can be flame hardened after machining.
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 1045 medium carbon steel?
A starting surface speed of 80 SFM with HSS and 300 SFM with carbide, and 70 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. 1045 medium carbon steel rates fair (about 57%) 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 1045 medium carbon steel
Other materials with a HSS drill
- 6061-T6 aluminum
- 7075-T6 aluminum
- 360 free-machining brass
- 932 bearing bronze
- 110 copper
- 12L14 leaded steel
- 1018 cold rolled steel
- 4140 alloy steel (annealed)
- All