Mechanical

• Strength

  The ability to withstand force without breaking or permanently bending.
• Bending Strength

  The ability to remain rigid and withstand deformation when subject to a force.
• Compressive Strength

  The ability to withstand pushing forces which attempt to crush or shorten the material
• Tensile Strength

  The ability to resist stretching or pulling forces

  The amount of energy required to bend a material= tensile strength.
• Shear Strength

  The ability to resist sliding forces acting against each other.
• Torsional Strength

  The ability to withstand twisting forces under tension or torque (twisting force).
• Plasticity

  The ability to be permanently changed in shape by an external force without cracking.

  e.g. hammer blows or pressure

  (metals and thermoplastic polymers are generally more plastic when heated.)
• Malleability

  The ability to be formed (worked, hammered, stretched, shaped, rolled) with the application of force

  (malleability increases with a rise in temperature e.g: metals and polymers)
• Ductility

  The ability to be drawn out. (can be deformed under pressure before cracking)

  Ductility decreases with temperature, so these materials are weaker at higher temperatures.
• Elasticity

  The ability to flex and bend when a force is applied and regain original/ normal shape when force is removed.
• Impact Resistance (toughnes)

  The ability to withstand sudden impact without fracture.

  It can also refer to a materials ability to withstand bending.

  (A tough material could be bent many times before it snaps the opposite would be brittle- snaps easily when bent)
• Hardness

  The ability to withstand abrasive wear (scratches) and indentation.
• Durability

  The ability to withstand wear and tear, weathering and the deterioration or corrosion this may cause.

  Weathering can change the appearance of a material and result in mechanical weakening.
• Fatigue resistance

  The ability to withstand alternating stresses over a long period of time without fracture (eg. living hinge on polypropylene)
• Stiffness

  Stiffness is the rigidity of an object — the extent to which it resists deformation in response to an applied force. The complementary concept is flexibility or pliability: the more flexible an object is, the less stiff it is.
• Rigidity

  The ability for a material to resist bending, stretching, twisting or other deformation under a load