Drill A36 hot rolled steel with HSS at about 75 SFM: 573 RPM for a 1/2 inch drill, 1,146 RPM for 1/4 inch, feeding about 0.0037 in/rev at 1/4 inch.
What RPM and feed for A36 hot rolled steel?
| Drill | RPM | Feed (in/rev) | Feed (IPM, capped 2500 RPM) |
|---|---|---|---|
| 0.0625" | 4,584 | 0.0009 | 2.34 |
| 0.125" | 2,292 | 0.0019 | 4.30 |
| 0.1875" | 1,528 | 0.0028 | 4.30 |
| 0.25" | 1,146 | 0.0037 | 4.30 |
| 0.3125" | 917 | 0.0047 | 4.30 |
| 0.375" | 764 | 0.0056 | 4.30 |
| 0.5" | 573 | 0.0075 | 4.30 |
| 0.625" | 458 | 0.0094 | 4.30 |
| 0.75" | 382 | 0.0112 | 4.30 |
Tools for cutting A36 hot rolled steel
How does A36 hot rolled steel machine?
A36 hot rolled plate and bar carries mill scale that is harder and more abrasive than the steel under it. Take the first cut deep enough to get under the scale in one pass rather than rubbing the tool on it.
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 A36 hot rolled steel?
A starting surface speed of 90 SFM with HSS and 325 SFM with carbide, and 75 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. A36 hot rolled steel rates fair 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 A36 hot rolled 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
- 1045 medium carbon steel
- All