Tensile strength

A quantitative comparison uses measured numerical values, such as density, tensile strength, compressive strength, melting temperature or cost. Numerical data allow a more precise decision, but values can only be compared directly when they describe the same property and use compatible units.

Tensile strength concerns pulling, whereas compressive strength concerns pushing or crushing. A material may perform very differently in the two tests.

Tensile strength concerns how much pulling stress a material withstands before breaking, while stiffness concerns how much it deforms under a force. These are not interchangeable: something can be stiff yet brittle. Glass and fired clay, for example, are rigid but can crack rather than bend.

For brick, the reported compressive strength is 50–140 MPa, compared with a tensile strength of only 7–14 MPa. Soda-lime glass similarly has a compressive strength of 360–420 MPa, compared with 31–35 MPa in tension. These ceramics resist squeezing much better than pulling.