Common Hardness Units

In machining, materials engineering, and quality control, hardness is a very important performance indicator. It reflects a material’s ability to resist localized plastic deformation (indentation or scratching).

1.Brinell Hardness (HB / HBW)

2.Rockwell Hardness (HRB / HRC)

3.Vickers Hardness (HV)

4.Shore Hardness (HS / Shore)

Brinell Hardness (HB / HBW)

Brinell hardness (HB) is generally used for relatively soft materials, such as non-ferrous metals, or steels before heat treatment or after annealing.

Principle:
A steel ball or carbide ball is pressed into the material surface, and the hardness is calculated by measuring the diameter of the indentation.

Characteristics:

Large indentation → stable data

Suitable for coarse-grained materials, castings, and forgings

Low surface requirement

Rockwell Hardness (HRB / HRC)

Rockwell hardness (HRC) is generally used for materials with higher hardness, such as after heat treatment.

Principle:
Hardness is determined based on the depth of penetration of an indenter (steel ball or diamond cone).

1.HRA: Uses a 60 kg load and a diamond cone indenter; suitable for extremely hard materials (such as cemented carbides).

2.HRB: Uses a 100 kg load and a 1.58 mm hardened steel ball; suitable for softer materials (such as annealed steel, cast iron, copper, aluminum, and low-carbon steel).

3.HRC: Uses a 150 kg load and a diamond cone indenter; suitable for very hard materials (such as quenched steel, tool steel, and heat-treated parts).

Characteristics:

Direct reading → high efficiency

Small indentation → suitable for finished parts inspection

Multiple scales (very important)

Vickers Hardness (HV)

The Vickers hardness test has a wide measurement range, covering materials from very soft to extremely hard.

Principle:
A diamond pyramid indenter is pressed into the material, and hardness is calculated by measuring the diagonal length of the indentation.

Characteristics:

High accuracy

Small indentation → suitable for micro-area testing

Applicable to almost all materials

Typical Applications:

• Thin layers (coatings, carburized layers)
• Precision parts
• Laboratory analysis

Shore Hardness (HS / Shore)

Shore hardness is a measure of a material’s resistance to indentation, mainly used for non-metallic materials such as rubber and plastics. The harder it is to press in, the higher the hardness; the deeper it penetrates, the lower the hardness.

Characteristics:

Portable

Fast

Suitable for non-metals

Typical Applications:

• Rubber (Shore A)
• Plastics (Shore D)