Material adjectives

Ductile

Drawn into a wire

Yield point

When the deformation is no longer entirely elastic (material extends rapidly).

Ultimate Tensile Strength (UTS)

Maximum stress a material can withstand when being stressed before it breaks

Breaking strength

Stress value at point of fracture

Strong

A large value for the UTS

Stiff

Large Young’s Modulus value

Brittle

Elastic behaviour up to breaking point, without plastic deformation.

Polymeric

Consist of long polymer chains.

Limit of proportionality

The value of stress beyond which stress is no longer proportional to strain.

Tough

Needs a large stress to break and create a new fracture surface.