It consists of a small split cylinder forming a mould 30 mm internal dia. and 30 mm high. On either side of the split cylinder, two parallel indicating arms with pointed ends are fixed.
Two loops of suitable material and strength soldered to the upper half of the mould on each side of the central split is provided to facilitate demoulding of the hardened paste specimen after test. The resilience of the mould shall be such that the action of a mass of 300g applied shall increase the distance between the indicator ends of the needle by 17.5mm ± 2.5mm without permanent deformation. The mould is supplied complete with two glass plates and lead weight.