Elastomer Compound Comparison: How the Major Seal Brands Stack Up
An honest, brand-by-brand comparison of how Parker Hannifin, Trelleborg, Freudenberg, and ERIKS name their elastomer compounds — and how to compare seals apples-to-apples by material family, hardness, temperature, and approvals instead of by trademark.
Why elastomer brand names confuse buyers
Ask three engineers what "Viton" is and you may get three answers. The reality: Viton® is a registered trademark of Chemours for a family of fluoroelastomers — the generic material is FKM. The same confusion repeats across every major seal supplier. Each brand markets the same underlying elastomer families under proprietary compound names, which makes apples-to-apples comparison surprisingly hard for procurement teams. This guide cuts through the branding so you can compare compounds by what actually matters: the material, the specification, and the approvals.
The proprietary-name problem
There are only a handful of base elastomer families used in industrial sealing — NBR, HNBR, FKM, EPDM, VMQ (silicone), FFKM, CR (neoprene), and AU/EU (polyurethane). Every seal manufacturer formulates within these families and then gives the result a house name. The chemistry is governed by the same ASTM and ISO standards; the marketing name is not. When you "compare brands," you are usually comparing labels on the same material class.
How the major seal brands name their compounds
Here is how the "Big Three" global seal manufacturers and ERIKS designate compounds within each material family.
| Brand | FKM is marketed as | FFKM is marketed as | Naming style |
|---|---|---|---|
| Parker Hannifin | Compound codes (e.g. V-series, Viton®-based) | Parofluor® | Alphanumeric compound codes (letter = family, digits = grade, suffix = hardness) |
| Trelleborg | FKM grades | Isolast® | Material grade names plus proprietary product-line brands |
| Freudenberg / Simrit | Numbered FKM compounds (e.g. 75 FKM 585) | Simriz® | Hardness + family + internal compound number |
| ERIKS | FKM compounds by grade and hardness | ERIKS FFKM compounds | Material family + hardness + application grade |
Brand and product names are the property of their respective owners and are listed only to show how each company designates equivalent material families.
A compound decoder by material family
Use this to translate any brand's compound name back to the generic family — the only attribute that truly determines chemical and temperature compatibility.
NBR (Nitrile / Buna-N)
The workhorse for petroleum oils, fuels, and hydraulic fluids below ~100 °C. Marketed by all brands simply as NBR or nitrile compounds at 70 Shore A for general service. Differences between brands are minor — mostly cure system and filler — and rarely change application suitability.
HNBR (Hydrogenated Nitrile)
A higher-temperature, more oil- and ozone-resistant upgrade to NBR, widely used in automotive air-conditioning and oilfield service. Every major supplier offers HNBR grades; the meaningful comparison is upper temperature limit and RGD resistance, not the brand.
FKM (Fluoroelastomer — "Viton" being a brand of this family)
The premium choice for high temperature and aggressive chemicals. Parker, Trelleborg, and Freudenberg all offer multiple FKM types (A, B, F, GLT/GFLT for low temperature). When comparing, match the FKM type and hardness — a standard Type A 75 Shore A from one brand is functionally equivalent to a standard Type A 75 Shore A from another.
EPDM
Best for steam, hot water, brake fluids, and outdoor weathering — but never for petroleum oils. All brands offer peroxide-cured and sulfur-cured EPDM; for potable water and steam, confirm the cure system and approvals rather than the brand.
FFKM (Perfluoroelastomer)
The highest chemical and temperature resistance available, and the most expensive. This is the one family where proprietary brands diverge most: Parker Parofluor®, Trelleborg Isolast®, Freudenberg Simriz®, and ERIKS FFKM grades each target specific chemical and temperature envelopes. Compare the published chemical-resistance and temperature data sheet directly.
What actually differs between brands — and what doesn't
| Attribute | Brand-dependent? | Notes |
|---|---|---|
| Dimensions (AS568 / ISO 3601) | No | Standardized worldwide — identical across all brands. |
| Base material family | No | NBR is NBR; FKM is FKM, regardless of trade name. |
| Exact compound formulation | Yes (minor) | Cure system, fillers, and plasticizers vary slightly; rarely changes fit-for-purpose. |
| Specialized proprietary grades (FFKM, RGD, ultra-low-temp) | Yes | Compare data sheets directly for critical applications. |
| Approvals (FDA, WRAS, NSF, USP VI) | Yes (per compound) | Must be matched explicitly — an approval on one compound does not transfer to another. |
| Availability & lead time | Yes | Often the deciding factor when material specs are equivalent. |
How to compare compounds apples-to-apples
- Strip the brand name. Identify the generic family (NBR, FKM, EPDM, etc.).
- Match hardness. Compare Shore A to Shore A.
- Compare service temperature range. Use the published upper and lower limits, not marketing claims.
- Check chemical compatibility against your actual media, using a compatibility chart.
- Confirm approvals if the application is regulated.
- Then compare price and availability. When two compounds are spec-equivalent, lead time and cost decide.
The bottom line: specify the material, not the brand
The "Big Three" — Parker Hannifin, Trelleborg, and Freudenberg — are excellent manufacturers, but their proprietary compound names can lock buyers into a single source for what is, in most cases, a standardized material. When you specify by elastomer family, hardness, temperature range, and approval, you open the door to equivalent compounds — including ERIKS elastomer products — that meet the same engineering requirement, often with better availability. For standard sealing applications, a correctly matched equivalent performs identically to the original.
Need help comparing a specific competitor compound to an ERIKS equivalent? Send us the compound name and your application conditions and we will return a spec-matched recommendation.
All third-party trademarks referenced — including Viton® (Chemours), Parofluor® (Parker Hannifin), Isolast® (Trelleborg), and Simriz® (Freudenberg) — are the property of their respective owners and are used only for identification and comparison. Tereefek Solutions and ERIKS are not affiliated with these companies.