BS ISO 812:2017

1   Scope This document specifies a method for determining the lowest temperature at which rubber materials do not exhibit brittle failure or the temperature at which half of the test pieces used in a test fail when impacted under specified conditions. The temperatures thus determined do not necessarily relate to the lowest temperature at which the material can be used since the brittleness will be affected by the conditions of test and especially by the rate of impact. Data obtained by this method are, therefore, intended to be used to predict the behaviour of rubbers at low temperatures only in applications in which the conditions of deformation are similar to those specified in the test. Three procedures are described:

       —  procedure A, in which the  brittleness temperature  is determined; 
   
   
     
       —  procedure B, in which the  brittleness temperature  for 50 %  failure  is determined; 
   
   
     
       —  procedure C, in which the test piece is impacted at a specified temperature. 
   
 

Procedure C is used in the classification of rubber materials and for specification purposes.

   NOTE  A similar test for rubber-coated fabrics is described in [ISO 4646](/search?q=ISO%C2%A04646).