TEST SIEVE (PERFORATED PLATE) : GHOSH TEST SIEVE: Perforated Plates are available in heavy gauge g.i or s.s.. round frame usually in 300mm or 450mm diameter, as per BIS Specification IS: 460. The perforated plates are made of mild steel or s.s. gauges as specified in the standards, and with square openings. However round opening perforated plates and frame dimensions as per the Customers specifica