HMS 1 vs HMS 2 — Heavy Melting Scrap Grades Explained

What Is Heavy Melting Scrap?

Heavy melting scrap, abbreviated as HMS, is the working term for obsolete steel scrap intended for re-melting in furnaces. It is the principal raw material of electric arc furnace mills, induction furnace plants, and many foundries. The grade specifications most widely used in international trade are those published by the Recycled Materials Association (formerly ISRI) in the United States.

The two main subdivisions of heavy melting scrap are HMS 1 and HMS 2. Both are heavy, both are steel, and both are destined for the furnace — but the specifications differ in important ways that affect price, mill suitability, and contract terms.

HMS 1 — Specification

Wrought iron and/or steel scrap, 1/4 inch and over in thickness. Individual pieces are not to exceed 60 inches in length by 24 inches in width, and the material must be prepared in a manner suitable for compact charging into the furnace. The grade is free of motor blocks, burnt material, sealed containers, and other excluded contamination.

In practice, HMS 1 is the cleaner of the two heavy melting grades. It is heavier, denser, and more consistent in composition, which makes it desirable for mills running stricter quality controls on their feed.

HMS 2 — Specification

Wrought iron and steel scrap, black and galvanised, 1/8 inch and over in thickness. The dimensional rules are similar to HMS 1 — individual pieces not exceeding 60 by 24 inches — but the minimum thickness drops to 1/8 inch, and the grade may include galvanised material as well as a wider range of lighter steel.

This means HMS 2 typically contains lighter material, more zinc-coated content, and somewhat lower bulk density than HMS 1. It is less expensive per tonne and is used by mills that can accommodate a wider quality range in their feed.

Why the Distinction Matters

The two grades trade at different price points. HMS 1 generally commands a premium of several dollars per tonne over HMS 2 in the same delivery, reflecting its cleaner profile and higher density. Mills choose between the two — or a blend of both — based on their furnace design, their alloy targets, and the price spread on the day.

Many international shipments are written as 80/20 HMS 1&2 — meaning 80% HMS 1 mixed with 20% HMS 2 — or as 70/30 or 50/50 blends. The blend ratio is one of the key commercial terms in any HMS contract.

Other Steel Scrap Grades

Beyond HMS 1 and HMS 2, the ReMA specifications cover a range of other steel scrap categories including shredded steel (high-density, magnetically separated, processed from automobile and miscellaneous scrap), bushelling (clean factory scrap from manufacturing operations), bonus (bundled new black sheet scrap), and plate and structural steel (P&S). For more on these, see the Steel Melting Scrap page on this site.