ISRI Aluminium Scrap Grades Explained: Tense, Taint/Tabor, Zorba, Twitch and More

When an Indian buyer asks for "Tense" or "Zorba 95" and a yard in Rotterdam or Houston replies with a price, both sides are relying on the same short names. Those names come from the ISRI scrap specifications, now published by the Recycled Materials Association (ReMA) at isrispecs.org. They are the closest thing the non-ferrous trade has to a common language.

This guide walks through the aluminium grades we see most often in shipments to India, quotes what each specification actually says, and covers the contract points that cause the most disputes. For alloy wheels (Troma) and used beverage cans, see our separate guides on [exporting alloy wheel scrap to India](https://metroxoverseas.com/blog/export-aluminium-alloy-wheel-scrap-troma-india) and [UBC scrap quality checks](https://metroxoverseas.com/blog/ubc-scrap-quality-checks).

## Why the code name matters

A grade code is shorthand for a full written specification: what the material is, what must be removed, and how much oil, grease or non-metallic content is tolerated. Every aluminium spec page on isrispecs.org lists the same tariff code, 7602.00.0096, which sits under Harmonized System heading 7602 for aluminium waste and scrap. The code tells customs what the cargo is. The grade name tells the buyer what quality to expect.

The specifications also carry general terms that apply unless the contract says otherwise. Two of them matter a lot in export deals (ReMA Nonferrous Terms, shown on each spec page):

- "Delivery of more or less of the specified quantity up to 3 percent is permissible." - "A ton shall be understood to be 2,000 pounds, unless otherwise specified."

That second line catches people out. Indian contracts are almost always priced per metric tonne (1,000 kg), while the ISRI default is the US short ton. If your contract says "ISRI specs apply", also write "price per metric tonne" so nobody argues about weight later.

## Cast aluminium grades

### Tense: Mixed Aluminium Castings

The ISRI text reads: "Shall consist of all clean aluminum castings which may contain auto and airplane castings but no ingots, and to be free of iron, brass, dirt and other non-metallic items. Oil and grease not to total more than 2%." ([ReMA spec: Tense](https://www.isrispecs.org/orpheus_resource/mixed-aluminum-castings/))

Tense is a workhorse feed for secondary smelters making casting alloys. The usual disputes are about iron: bolts, bushes and steel inserts left in engine and gearbox castings. Photos showing broken-open pieces help more than wide shots of a pile.

### Tread: Segregated New Castings, Forgings and Extrusions

"Shall consist of new, clean, uncoated aluminum castings, forgings, and extrusions of one specified alloy only and to be free from sawings, stainless steel, zinc, iron, dirt, oil, grease and other non-metallic items." ([ReMA spec: Tread](https://www.isrispecs.org/orpheus_resource/segregated-new-aluminum-castings-forgings-and-extrusions/))

The key words are "new" and "one specified alloy". Tread is usually production offcuts, and buyers will expect the alloy to be named on the offer.

## Sheet and siding grades

### Taint/Tabor: Clean Mixed Old Alloy Sheet

"Shall consist of clean old alloy aluminum sheet of two or more alloys, free of foil, venetian blinds, castings, hair wire, screen wire, food or beverage containers, radiator shells, airplane sheet, bottle caps, plastic, dirt, and other non-metallic items. Oil and grease not to total more than 1%. Up to 10% Tale permitted." ([ReMA spec: Taint/Tabor](https://www.isrispecs.org/orpheus_resource/clean-mixed-old-alloy-sheet-aluminum/))

### Tale: Painted Siding

"Shall consist of clean, low copper aluminum siding scrap, painted one or two sides, free of plastic coating, iron, dirt, corrosion, fiber, foam, or fiberglass backing or other non-metallic items." ([ReMA spec: Tale](https://www.isrispecs.org/orpheus_resource/painted-siding/))

Notice how the two link: Taint/Tabor allows up to 10% painted siding. If a load is mostly painted material, it should be offered as Tale, not Taint/Tabor.

## Shredded grades from auto shredders

### Zorba: Shredded Non-ferrous Scrap (predominantly aluminium)

Zorba is the mixed non-ferrous fraction recovered after shredding, mainly from end-of-life vehicles. The spec says it is made up of aluminium, copper, lead, magnesium, stainless steel, nickel, tin and zinc, "generated by eddy current, air separation, flotation, screening, other segregation technique(s)", and that it "shall have passed one or more magnets" and "shall be free of radioactive material, dross, or ash". ([ReMA spec: Zorba](https://www.isrispecs.org/orpheus_resource/shredded-nonferrous-scrap-predominantly-aluminum/))

The number after the name matters most: "'Zorba 90' means the material contains approximately 90% nonferrous metal content." Always state the Zorba number, and agree how it will be checked. The spec itself leaves the split between metals to "agreement between buyer and seller".

### Twitch: Floated Fragmentizer Aluminium Scrap

Twitch is an upgraded, mostly aluminium product from wet or dry media separation. The spec requires that it "must be dry and not contain more than 1% maximum free zinc, 1% maximum free magnesium, and 1% maximum of analytical iron", with "a total 2% maximum of non-metallics, of which no more than 1% shall be rubber and plastics". It must also be free of "air bag canisters, or any sealed or pressurized items". ([ReMA spec: Twitch](https://www.isrispecs.org/orpheus_resource/floated-fragmentizer-aluminum-scrap-from-automobile-shredders/))

### Ginger: Shredded Aluminium Cast

Ginger is a newer grade, shown on isrispecs.org with an effective date of 19 June 2026. It is "mixed shredded cast aluminum that is mechanically segregated from Zorba and Twitch", must be dry, with no more than 1% each of free magnesium, free zinc and free iron, and no more than 1% non-metallics. ([ReMA spec: Ginger](https://www.isrispecs.org/orpheus_resource/shredded-aluminum-cast/))

Because Ginger is new, not every buyer or inspector will know it by name yet. Quote the full description alongside the code until it becomes familiar.

## Radiator grades

### Tally: All-Aluminium Radiators

"Shall consist of clean aluminum radiators and/or condensers. Should be free of all other types of radiators. All contaminants including iron, plastic, and foam not to exceed 1% of weight." ([ReMA spec: Tally](https://www.isrispecs.org/orpheus_resource/all-aluminum-radiators-from-automobiles/))

### Talk: Aluminium-Copper Radiators

"Shall consist of clean aluminum and copper radiators, and/or aluminum fins on copper tubing, free of brass tubing, iron and other foreign contamination." ([ReMA spec: Talk](https://www.isrispecs.org/orpheus_resource/aluminum-copper-radiators/))

Tally and Talk are priced very differently because of the copper. Mixing them in one container without saying so is a common cause of claims.

## Turning a grade name into a clean contract

The ISRI specifications are a starting point, and several of them say so directly: variations are to be agreed between buyer and seller. For shipments to India, we suggest the contract covers at least:

1. **Grade code plus the full description.** Write "Tense (ISRI/ReMA), mixed aluminium castings" rather than the code alone. 2. **Agreed limits that differ from the spec.** For example, a tighter iron limit on Tense, or the Zorba number. 3. **Weight basis.** Metric tonnes, and whether net or gross. 4. **Quantity tolerance.** The ISRI default is plus or minus 3%. Say so if you want something different. 5. **Inspection and evidence.** Loading photos, and a pre-shipment inspection certificate where required. Our [PSIC guide](https://metroxoverseas.com/blog/pre-shipment-inspection-metal-scrap-india-psic) explains when India requires one. 6. **What happens if quality differs.** A defined claim procedure saves weeks of arguments.

## Sources

- ReMA (formerly ISRI) Scrap Specifications, aluminium grades: Tense, Tread, Taint/Tabor, Tale, Zorba, Twitch, Ginger, Tally and Talk, each linked above, plus the Nonferrous Terms shown on each spec page. https://www.isrispecs.org/ - DGFT Handbook of Procedures 2023, para 2.51 (import conditions for metal scrap): https://content.dgft.gov.in/Website/dgftprod/e1cb52ea-0c3a-4c2a-8cd7-dd992e9bdc98/HBP_2023.pdf

*This article provides general market information. Specifications are quoted from isrispecs.org as of October 2026. Grade, quality and commercial terms must be agreed and verified for each transaction.*

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