Heavy melting steel is a designation for recyclable steel. It is categorised into two major categories: HMS 1 and HMS 2. The difference between the two is HMS 1 does not contain galvanized and cast iron, whereas HMS 2 does. Because both grades guarantee a minimum piece thickness â?? at least 1/4inch (6.3mm) for HMS 1, and 1/8 in for HMS 2 â?? consignments have a high density. The typical constituents are plates, truck parts, structural items, large machinery parts, automatic parts, pipes, post consumer steel goods. Chemical Composition: C:0.06 â?? 0.082% Mn:0.75 â?? 1.05% SI:0.13 â?? 0.28% P: Max 0.035% S: Max 0.045% Ar: Max 0.15%