TSR10 and TSR20 are both technically specified rubbers made from field coagulum and graded by laboratory tests. TSR10 has tighter limits (0.08% dirt against 0.16%, and a higher minimum PRI) and costs more. RSS, ribbed smoked sheet, is made from fresh latex, graded visually and usually sold at a premium to both. Most tyre and rubber goods makers use TSR20 as their main grade and buy TSR10 or RSS only where a compound needs it.
This guide compares the three grades for buyers. Our main page on TSR20 natural rubber covers what we supply from Liberia.
The grades side by side
| Property | TSR10 | TSR20 | RSS3 |
|---|---|---|---|
| Raw material | Field coagulum, fresher material | Field coagulum (cup lump, tree lace) | Fresh field latex |
| How it is graded | Laboratory tests (ISO 2000) | Laboratory tests (ISO 2000) | Visual, against the Green Book |
| Dirt max | 0.08% | 0.16% | Not tested; visual limits on specks |
| Ash max | 0.60% | 0.80% | Not tested |
| PRI min | 50 | 40 | Not tested |
| Packing | Bales | Bales | Bales of sheets |
| Typical use | Higher fatigue parts, some tyre components | Tyre carcass, truck tyres, general goods | Treads, high strength and light coloured goods |
| Relative price | Small premium to TSR20 | Reference grade | Premium to TSR20 |
TSR20
TSR20 is made by cleaning, crumbling, washing, drying and baling field coagulum. Because it is graded in a laboratory, it is consistent from lot to lot when the factory is well run. It is the grade traded on the SICOM TSR20 futures contract, which makes it the price reference for most technically specified rubber.
For tyre makers, TSR20 is the workhorse. It goes into carcasses, sidewalls, truck and bus tyres and most moulded and extruded goods. Its weakness is variability in Mooney viscosity and PRI between origins and factories, which is why buyers often add limits beyond the grade. See TSR20 specifications explained.
TSR10
TSR10 is made from similar raw material to TSR20, but with cleaner and fresher coagulum and closer process control. It meets tighter limits for dirt, ash and PRI. Buyers choose it where dirt particles would shorten the fatigue life of a part, such as engine mounts and some tyre components.
The premium over TSR20 is usually modest, but supply of TSR10 is thinner in West Africa. We supply both TSR10 and TSR20 from Liberia; for TSR10, ask early so we can plan volume. When you compare offers, check that both grades are quoted against the same ISO 2000 edition and test methods.
RSS (ribbed smoked sheet)
RSS is made from fresh latex coagulated in trays, rolled into ribbed sheets and dried in smokehouses. Grades from RSS1 to RSS5 are set by visual inspection against the International Standards of Quality and Packing for Natural Rubber Grades, known as the Green Book. RSS3 is the most traded.
RSS has high tensile strength and good green strength, which is why it is used in tyre treads and in products that need high strength. Because it is graded by eye, quality can vary within a grade, and it needs more careful inspection at loading.
RSS is produced mainly in Thailand, India and other Asian origins. West African production is mostly technically specified rubber.
How to choose
- Start with TSR20 for carcass, sidewall, truck tyre and general goods compounds.
- Move to TSR10 where dirt limits fatigue life, or where you need a guaranteed higher PRI.
- Use RSS where your compound has been developed around its strength, and keep a TSR alternative qualified.
- Specify, do not assume. Two TSR20 lots from different origins can process very differently. Qualify each origin with a trial lot before committing volume.
Where a grade is sourced also matters, for freight, EUDR exposure and reliability. See Liberia vs Côte d'Ivoire vs Southeast Asia as rubber origins.
Pricing between grades
All three grades move with the same physical market, but the spreads between them change with supply. TSR10 usually trades a small premium to TSR20. RSS3 has its own futures contracts in Asia and often trades at a wider premium, which can narrow or widen sharply when weather cuts sheet production. Our note on natural rubber price drivers explains how physical cargo is priced against SICOM.
If you are reviewing grades for a new compound, tell us the application when you request a quote and we will advise which grade and limits fit.