The test sample is supported over its whole area and precautions shall be taken to ensure that particles will not be scattered upon fragmentation. Then the test sample is shattered with a centre punch placed approximately 15 mm in from the midpoint of one of the longer edges of the test sample. After a maximum of 5 min of fracture, and without using any aid to vision,except spectacles if normally worn, the particles are counted in a square of 50 mm side located approximately at the centre of the area of coarsest fracture and excluding any area
within 15 mm of any edge or hole.

The test sample shall fragment in such a way that the number of particles counted in a square
with sides of 50 mm shall not be less than 45.

The sample under test is broken by means of a test punch having a head with a mass of 75 g
± 5 g and a conical tungsten carbide tip with an angle of 60° ± 2°.