When a scrap offer says "HMS 1&2 80:20" or "Birch/Cliff", it is using the ISRI grading system — the most widely used reference for international scrap trade. Knowing what these codes mean helps you compare offers like-for-like and write clearer purchase contracts.
What are ISRI specifications?
ISRI specifications come from the Scrap Specifications Circular first published by the Institute of Scrap Recycling Industries in the United States. The organisation now operates as the Recycled Materials Association (ReMA), but traders worldwide still refer to the grades as "ISRI".
Ferrous (iron and steel) grades are identified by numbers, mostly in the 200 series. Non-ferrous grades such as copper, aluminium, and brass use code words — Berry, Birch, Candy, Tense, Zorba, and so on. Each definition sets out what material is allowed, the size or thickness, and which contaminants are limited.
Ferrous: HMS 1 and HMS 2
Heavy Melting Scrap (HMS) is the most traded ferrous scrap grade and the main feedstock for electric arc and induction furnaces.
- HMS 1 — wrought iron and steel scrap 1/4 inch (about 6 mm) and thicker, cut to a maximum size. It is heavier and cleaner, so it usually commands a higher price.
- HMS 2 — also allows thinner material, including black and galvanised steel, so it melts with a lower yield than HMS 1.
- Blends — HMS is often traded as a mix such as "HMS 1&2 80:20", meaning roughly 80% HMS 1 and 20% HMS 2 by weight.
Copper grades
Copper scrap grades separate material by form (wire, solids, tubing) and purity. The higher the copper content and the cleaner the material, the closer the price sits to the copper exchange price.
- Barley — bare bright copper wire: clean, uncoated, unalloyed wire. The top copper scrap grade.
- Berry — No. 1 copper wire: clean, untinned, uncoated copper wire.
- Candy — No. 1 heavy copper: clean copper solids and tubing.
- Birch — No. 2 copper wire: may have coating or tin; nominally around 96% copper with a lower minimum.
- Cliff — No. 2 copper solids and mixed heavy copper.
Aluminium grades
Aluminium grades are defined by the source of the material (castings, sheet, wire, cans) and how it has been processed.
- Tense — mixed aluminium castings, free of iron, dirt, and other contaminants.
- Zorba — shredded mixed non-ferrous metal, mostly aluminium, recovered from shredding operations. It also contains copper, brass, and other metals.
- Twitch — floated, fragmentised aluminium from shredders, cleaner than Zorba.
- Taldon — used beverage cans (UBC).
How to use grades in a purchase contract
An ISRI code is a starting point, not the whole specification. For every lot, agree the following in writing:
- The exact grade or blend ratio (for example HMS 1&2 80:20).
- Tolerances for moisture, non-metallics, and any restricted material.
- Maximum piece size if your furnace or shredder has limits.
- Who performs the pre-shipment inspection and how disputes on arrival are settled.
The short version
Grades let buyers and sellers speak the same language, but definitions are updated from time to time. Always check the current specification and write the grade, tolerances, and inspection terms into your contract. If you are unsure which grade suits your process, tell us your furnace type and end product and we will suggest options.
