Impact strength

Description

The maximum impact from a hard blow that a material can withstand before breaking. The standard testing methods for impact strength are the Charpy method and the Izod method. Both methods place a notch in the material on the side opposite the striking position. This localizes the stress and induces a brittle fracture that is independent of the effects of velocity. Both tests provide the impact strength in foot-pounds of energy required for breakage. A high impact strength indicates that a material is tough and not brittle. Impact strength tests are often done on metals, hard rubber, plastics, portland cement and glass.

Synonyms and Related Terms

impact resistance; Stossfestigkeit (Deut.); résistance à l'impact (Fr.);

Authority

• Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976

• Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971

• Hoechst Celanese Corporation, Dictionary of Fiber & Textile Technology (older version called Man-made Fiber and Textile Dictionary, 1965), Hoechst Celanese Corporation, Charlotte NC, 1990