Types of Steel Scrap: Ferrous Metal Grading & Industrial Classification
Steel scrap constitutes over 85% of total industrial metal recycling volume worldwide. Understanding the specific physical properties, dimensions, and chemical thresholds of different steel scrap grades ensures sellers secure maximum value from foundries and steel rolling mills.
Key Takeaways for Industrial Sellers:
- HMS 1 requires a minimum steel thickness of 6mm (1/4 inch) and individual pieces under 1.5 meters.
- HMS 2 contains lighter steel sections between 3mm and 6mm thickness, including galvanized materials.
- Light Melting Scrap (LMS) encompasses sheet punchings and thin steel under 3mm.
- Heavy structural sections (ISMB, ISMC, thick plates) command the highest melting yields and premium pricing.
1. Heavy Melting Steel: HMS 1 vs HMS 2
The international standard ISRI (Institute of Scrap Recycling Industries) codes 200–206 define Heavy Melting Steel. In Indian industrial trading, HMS is the primary benchmark commodity traded across Karnataka steel centers.
HMS 1 designates clean wrought iron or steel scrap with a minimum thickness of 6 mm (0.25 inches). Examples include heavy structural beam cut-offs, ship plates, boiler plates, thick machinery chassis, and large diameter pipes.
HMS 2 covers thinner steel components with thicknesses between 3 mm and 6 mm. This includes galvanized steel sheets, automotive stampings, light tubing, and demolition steel with minor surface coatings.
- HMS 1: Thickness ≥ 6mm, density > 0.7 MT/m³, zero galvanized coatings.
- HMS 2: Thickness 3mm to 6mm, allows coated or galvanized steel sections.
- Pricing: HMS 1 typically trades at a 5% to 10% premium over HMS 2 due to lower oxidation loss during furnace melting.
2. Fabrication Scrap & Plate Punchings
Industrial manufacturing clusters like Bangalore's Peenya, Bommasandra, and Jigani generate vast volumes of fabrication offcuts from laser cutting, plasma cutting, and mechanical stamping operations.
New Production Plate Punchings (ISRI 207) represent pure, unrusted carbon steel with negligible paint or corrosion. Foundries prize plate punchings because of their predictable chemistry and high charging density in electric induction furnaces.
3. Machine Turnings & Borings (Swarf)
CNC machine shops produce continuous curled shavings (turnings) or finely broken chips (borings). Because turnings retain significant cutting oil coolant and have high surface area, they are subject to oxidation and moisture deductions during commercial purchasing.
Storing turnings on paved concrete slopes with oil-recovery sumps significantly improves their resale value and prevents environmental contamination.