The instrument is designed to test specimens from 50 mm dia to 100 mm dia having thickness equal to half of the diameter for determination of Indirect Tensile Strength. A pair of loading jaws, designed so as to contact a disc shaped sample at diametrically opposed surfaces over an arc of contact of about 10 degrees at failure, is supplied. The set of jaws supplied with the equipment is designed for 50 mm dia specimen and therefore it is essential to order jaws for required sizes, if the samples of other diameters are to be tested. A set of plain platens are provided with the jack to enable testing of cube and circular specimens upto 50 mm size for compressive strength.