Complete material hardness conversion chart with Brinell, Rockwell, and Vickers hardness scales. Essential reference for CNC machining material selection and cutting parameter optimization.
Material hardness is a critical factor in CNC machining that affects tool selection, cutting parameters, and machining strategies. Different hardness scales are used depending on the material type and application requirements.
Brinell (HB) is used for softer materials, Rockwell B (HRB) for medium hardness materials, Rockwell C (HRC) for hardened steels, and Vickers (HV) provides the most versatile scale across all hardness ranges.
| Brinell (HB) | Rockwell B (HRB) | Rockwell C (HRC) | Vickers (HV) | Typical Material | Machinability |
|---|---|---|---|---|---|
| 100 | 56 | N/A | 105 | Soft aluminum alloys | Excellent |
| 150 | 78 | N/A | 155 | Brass, soft steel | Very Good |
| 200 | 92 | N/A | 210 | Medium carbon steel | Good |
| 250 | 99 | 20 | 260 | Tool steel (annealed) | Good |
| 300 | N/A | 30 | 315 | Heat treated steel | Fair |
| 350 | N/A | 37 | 370 | Hardened steel | Fair |
| 400 | N/A | 42 | 420 | Tool steel | Difficult |
| 450 | N/A | 47 | 475 | Hardened tool steel | Difficult |
| 500 | N/A | 51 | 525 | High carbon steel | Very Difficult |
| 550 | N/A | 55 | 580 | Spring steel | Very Difficult |
| 600 | N/A | 58 | 630 | File hard steel | Extremely Difficult |
| 650 | N/A | 61 | 685 | Hardened die steel | Grinding Required |
| 700 | N/A | 63 | 740 | Very hard tool steel | Grinding Required |
| Material Category | Hardness Range | Characteristics |
|---|---|---|
| Aluminum Alloys | 15-150 HB | Soft, excellent machinability, good corrosion resistance |
| Brass & Bronze | 50-200 HB | Good machinability, corrosion resistant, decorative |
| Mild Steel | 120-200 HB | Good weldability, easy to machine, general purpose |
| Carbon Steel | 150-300 HB | Heat treatable, moderate machinability, structural applications |
| Alloy Steel | 200-400 HB | High strength, heat treatable, specialized applications |
| Tool Steel | 200-700 HB | Very hard when heat treated, wear resistant, cutting tools |
| Stainless Steel | 150-500 HB | Corrosion resistant, work hardening, food grade applications |
| Cast Iron | 150-300 HB | Good machinability, vibration damping, engine blocks |
Range: 1-650
Range: 1-100
Range: 20-70
Range: 1-3000
Our CNC machining services handle materials from soft aluminum to hardened tool steels with precision and expertise.