New, clean, single-alloy aluminium castings, forgings and extrusions, free of sawings, iron and coatings. One of the highest-value aluminium grades — ideal for smelters and die-casters needing predictable melt chemistry (6063 billet, A380, A356).

ISRI Grade Name: Tread

ISRI Description and Specification

Tread is defined as new, clean, uncoated aluminium castings, forgings, and extrusions produced from a single, specified alloy. Each lot must consist entirely of one alloy type — mixed-alloy Tread is not permissible under the specification. Individual pieces may originate from aerospace, automotive, industrial machinery, or consumer goods manufacturing, provided they are newly generated as production offcuts or out-of-spec parts rather than post-consumer scrap. The material must be free of sawings, turnings, or borings. It must not contain stainless steel inserts, zinc components, iron attachments, or any other non-aluminium material. Dirt, oil, and grease must be absent — the material must be dry, clean, and uncontaminated at the time of sale. The single-alloy requirement is critical: it preserves the chemical integrity of the lot, ensuring that the receiving smelter or die-caster can charge it directly without extensive pre-sorting or alloy adjustments. Tread is one of the highest-value aluminium scrap grades precisely because of this purity and the absence of downgrading contaminants.

Why Tread Commands Premium Value

Because Tread material is sourced directly from manufacturing plants — press shops, die-casting floors, extrusion houses, and machining facilities — it carries none of the contamination risks associated with post-consumer or post-industrial mixed scrap. The single-alloy nature of the material means that a smelter receiving Tread can reliably predict the melt composition without requiring extensive spectrometric verification of each batch. This translates into lower processing costs, faster turnaround, and higher-grade secondary aluminium ingots at the output. In commodity terms, Tread typically commands a significant premium over mixed grades like Tense or Taint/Tabor, reflecting both its quality and its predictability for the end user.

Who Uses Tread Scrap

The primary consumers of Tread scrap are secondary aluminium smelters and die-casting alloy producers who require single-alloy, clean feedstock to produce specific secondary alloy ingots (e.g., A380, A356, 6063 billet). In India, this includes producers of automotive die-casting alloy ingots who supply to OEM component manufacturers — particularly in the two-wheeler, passenger car, and commercial vehicle sectors, where aluminium castings are used extensively in engine blocks, transmission housings, brake calipers, and suspension components. Aerospace sub-component manufacturers and precision engineering firms who melt and re-cast to tight tolerances also prefer Tread-grade material. Extrusion billet producers converting scrap into 6xxx-series billet are another key end-user, since single-alloy clean material allows them to maintain alloy chemistry within narrow specification windows. Additionally, defence and high-performance manufacturing sectors that require certified secondary aluminium with traceable chemistry specifications may source Tread-grade material for controlled-melt production runs.

Logistics and Trade Notes

Tread is typically traded in containers (20-foot or 40-foot), with material loose-loaded or palletised depending on form factor. Because of its single-alloy requirement, pre-shipment inspection (PSI) and spectrometric verification at origin are standard practice for large consignments. Moisture is rarely an issue given the dry, indoor origin of the material, but loading inspection for iron or stainless contamination is advisable. Origin countries with strong aluminium extrusion and casting industries — USA, Germany, South Korea, Japan, UAE (re-export), and Canada — are the dominant supply sources.