# Compressive Strength

A material′s ability to resist a force that tends to crush or buckle.

Compressive Strength is the maximum compressive load a specimen sustains divided by the specimen′s original cross-sectional area. Note: "Original" cross-sectional area.

- For metals, the compressive strength is the same as the tensile yield strength.
- Polymers are approximately 20% stronger in compression than in tension.
- Ceramics, compressive strength is governed by crushing and is much larger than the tensile strength.
- Composites which contain fibres (including natural composites like wood) are a little weaker (up to 30%) in compression than tension because the fibres buckle.

The compressive strength of a material that fails by shattering fracture can be defined within fairly narrow limits as an independent property. However, the compressive strength of materials that do not shatter in compression must be defined as the amount of stress required to distort the material an arbitrary amount.

**See also: **Compressive Yield Strength, Crushing Load, Eccentricity of Loading, Strength, Tensile Strength.

**Subjects: ** Mechanical Engineering