Material Hardness Chart

Material hardness measures how well a surface resists dents, scratches, and wear. Engineers test it by pressing a small object into the material and measuring the mark. Harder metals last longer but are tougher to machine. Softer metals cut faster but wear out sooner.

Each test uses a different tool and force. Brinell (HB) presses a steel or carbide ball into the surface. It works best for softer metals like aluminum and brass. Rockwell (HRB/HRC) uses a diamond cone or steel ball. It gives fast results for steels and hardened alloys. Vickers (HV) uses a diamond pyramid. It works on all materials, even thin coatings and small parts.

For soft metals like aluminum and brass, use Brinell (HB) or Rockwell B (HRB). For steels and hardened alloys, use Rockwell C (HRC). For thin parts, coatings, or very hard materials, use Vickers (HV). Most CNC shops list steel hardness in HRC. It is fast and widely understood.

Yes. Harder materials wear out tools faster and need slower speeds. Softer materials cut faster but may gum up the cutter. Most CNC-friendly metals fall between 80 HRB and 35 HRC. Above 45 HRC, you may need carbide or ceramic tooling and slower feed rates.

Yes. Heat treatment, case hardening, and nitriding can all change hardness after machining. Many parts are machined soft and then hardened. This saves tool wear and helps hold tight tolerances. Plan your heat treatment step before you finalize the design.