Brittleness Temperature ASTM D746 ISO 974

Brittleness Temperature of Plastics and Elastomers by Impact ASTM D746, ISO 974

Scope:
Brittleness temperature is the temperature at which 50% of the tested specimens exhibit brittle failure at specified impact conditions. It is utilized primarily for plastics and elastomers.

Test Procedure:
Specimens are secured in the customer specified specimen holder (A or B) with a torque wrench at 5 in-lb. The specimen holder is lowered into a bath at a specified temperature. The specimens are impacted at 2000 ± 200 mm/s and then examined. The procedure is repeated at a lower temperature until enough data is generated to determine a brittleness temperature. Brittle temperature is the temperature at which 50% of the specimens fail. Brittle failure is defined by ASTM D746 as fracture into 2 or more pieces, or any crack visible to the unaided eye. The specimens can be bent to an angle of 90° and examined for cracks at the bend.

Data:
Test temperatures, number of failures and the determined brittleness temperature.

Specimen size:
There are three specimens: Type I, Type II or Type III. ASTM specimens are Type I at 6.35 mm by 31.75 mm by 1.91 mm thick. ISO specimens are Type III at 20 mm by 2.5 mm and 2.0 mm thick.

**Please note that this test description is intentionally generic in nature and aimed at providing a descriptive summary to enhance test understanding. Due to copyright restrictions, we are not able to provide copies of standards. Standards can be obtained from appropriate standards authorities.