Drill 932 bearing bronze with HSS at about 80 SFM: 611 RPM for a 1/2 inch drill, 1,222 RPM for 1/4 inch, feeding about 0.0037 in/rev at 1/4 inch.
What RPM and feed for 932 bearing bronze?
| Drill | RPM | Feed (in/rev) | Feed (IPM, capped 2500 RPM) |
|---|---|---|---|
| 0.0625" | 4,889 | 0.0009 | 2.34 |
| 0.125" | 2,445 | 0.0019 | 4.58 |
| 0.1875" | 1,630 | 0.0028 | 4.58 |
| 0.25" | 1,222 | 0.0037 | 4.58 |
| 0.3125" | 978 | 0.0047 | 4.58 |
| 0.375" | 815 | 0.0056 | 4.58 |
| 0.5" | 611 | 0.0075 | 4.58 |
| 0.625" | 489 | 0.0094 | 4.58 |
| 0.75" | 407 | 0.0112 | 4.58 |
Tools for cutting 932 bearing bronze
How does 932 bearing bronze machine?
SAE 660 (C932) bearing bronze is the usual stock for bushings. It machines cleanly into small broken chips. Like brass it can grab a drill, so a flatted drill lip helps, and it runs happily dry.
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 932 bearing bronze?
A starting surface speed of 90 SFM with HSS and 300 SFM with carbide, and 80 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. 932 bearing bronze rates good 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 932 bearing bronze
Other materials with a HSS drill
- 6061-T6 aluminum
- 7075-T6 aluminum
- 360 free-machining brass
- 110 copper
- 12L14 leaded steel
- 1018 cold rolled steel
- 1045 medium carbon steel
- 4140 alloy steel (annealed)
- All