# NBR elastomer

Selecting nitrile rubber by polymer grade, compound, cure, fluid exposure and seal-test conditions.

Reviewed: 2026-11-01

Tags: materials, polymers, elastomers, nbr

NBR, or nitrile rubber, is an acrylonitrile-butadiene copolymer family used in seals, hoses and other oil-resistant components. The family designation does not specify one formulation, hardness, low-temperature limit or service life. Identify the complete compound and finished-part requirements before assigning a compatibility or temperature rating.

## Polymer grade is only the starting point

Parker's **N0674 NBR** gives **14% typical compression set at 100°C** and **34% at 125°C**. Both tests run **70 h** under **DIN ISO 815-1**, with **25% deformation**, **specimen B, method A**. The **20-point** change is temperature-specific. Assess seal life and operating limits separately. [Parker N0674 test table](https://www.parker.com/content/dam/Parker-com/Literature/Praedifa/Compound_Data_Sheets/EMG_PTD_Compound-Data-Sheet_NBR_N0674_EN.pdf)

ZEON's Nipol NBR overview describes a portfolio with different acrylonitrile content, polymerization chemistry, processability and supplied forms. Its range includes conventional polymers, NBR/PVC blends, pre-crosslinked and carboxylated products, offered as powder, crumb, liquid or bale. These are raw-material choices; none alone defines the properties of a cured seal.

ZEON specifically identifies acrylonitrile content as a way to balance low-temperature behavior and fuel resistance. Preserve the polymer grade and formulation instead of treating all materials called nitrile as equivalent. The cited webpage is undated; its crawl record is not a publication revision. [ZEON Chemicals, Nipol NBR](https://www.zeonchemicals.com/products/nipol-nbr/)

The distinction remains visible even within a similar chemistry. ZEON Corporation lists **Nipol 1042** and **1052J** with the same **33.5% bound ACN** design value but different listed Mooney viscosities, **77.5 and 46.0**, respectively. Matching ACN content therefore does not identify one processing grade. Its table labels these entries design values, not a delivered-batch certificate. [ZEON Corporation, NBR product series](https://www.zeon.co.jp/en/business/enterprise/rubber/nbr/)

## ACN content and hydrogenation change the selection

Apple Rubber's material guide explains that increasing acrylonitrile content improves oil resistance at the cost of low-temperature performance. It separately identifies **HNBR** as hydrogenated nitrile, with saturation of the polymer chain improving ozone/weathering behavior. HNBR is consequently a separate material selection, not a different spelling of NBR.

The guide also warns that an elastomer being suitable for an application means some compounds may qualify, not every compound of that family. Do not copy a family-level temperature range or application list into a finished-part approval. Its cited edition is not assigned a revision date from the PDF filename. [Apple Rubber, Material Selection Guide](https://applerubber.s3.us-east-1.amazonaws.com/sdg/pdf/MaterialSelectionGuide.pdf)

## Named compound data: Parker N0674

Parker's **N0674 black NBR** sheet has **creator and print dates May 17, 2024**. Selected typical results are:

| Test | Typical result | Basis |
| --- | ---: | --- |
| Hardness | 72 Shore A | DIN ISO 48-4; specimen greater than 6 mm |
| Tensile strength | 16.2 N/mm² | DIN 53504; S2 specimen |
| Compression set | 14% | 70 h at 100 °C; DIN ISO 815-1 |
| Compression set | 34% | 70 h at 125 °C; DIN ISO 815-1 |
| TR10 | −25 °C | ISO 2921; 2 mm specimen |

Both compression-set tests use **25% deformation, specimen B, method A**. Parker says its mean laboratory values are typical, not specification values, and may differ from finished-goods measurements. These results establish neither seal leakage nor a universal NBR temperature limit. [Parker, N0674 Compound Data Sheet](https://www.parker.com/content/dam/Parker-com/Literature/Praedifa/Compound_Data_Sheets/EMG_PTD_Compound-Data-Sheet_NBR_N0674_EN.pdf)

## “Oil resistant” needs the actual fluid

Trelleborg's NBR coated-fabric guidance identifies resistance to many petroleum-based fluids, oils and greases, while listing ozone, ketones, esters, aldehydes, chlorinated and nitro hydrocarbons as attack concerns. This is family guidance in a coated-fabric context, not a qualification of a molded O-ring or every commercial fuel blend. Its PVC-blend exception also reinforces the need to retain formulation identity. [Trelleborg Engineered Coated Fabrics, NBR](https://www.trelleborg.com/en/engineered-coated-fabrics/solutions/coatings/nbr)

Chemours' hosted chemical-resistance evaluation guidance states that ratings draw on test data, supplier agreement and sometimes analogy or experienced judgment. It emphasizes temperature, static versus dynamic duty, polymer grade and formulation. A room-temperature chart is therefore a screening aid, not evidence for a hot, moving seal in a mixture. Define concentration, additives, contaminants, temperature, duration and acceptable retained properties before qualification. [Chemours/TLARGI, Chemical Resistance Guide Evaluation Method](https://chemours-util.my.salesforce-sites.com/CRG_TlargiEvalMethod)

## Cure and thermal history matter

Trelleborg's rotary-seal catalog, explicitly **Edition April 2026**, discusses sulfur-bearing hypoid-oil additives and secondary curing/hardening of nitrile under particular hot-oil conditions. Its broader temperature tables warn that media composition can cause significant deviations from guidance values. A lubricant designation or generic NBR temperature chart cannot resolve every additive package and exposure.

Retain the qualified compound and cure route, then test the actual lubricant at the required temperature and duty. Do not infer a universal cure recipe from the polymer family or assume that changing to HNBR or another elastomer automatically preserves all properties. [Trelleborg Sealing Solutions, Rotary Seals, material and lubricant guidance](https://www.trelleborg.com/seals/-/media/tss-media-repository/tss_website/pdf-and-other-literature/catalogs/rotary_gb_en.pdf?rev=dea9fee9291342659839a425c17b7a30)

## Qualify and release the assembly

For a seal, record gland dimensions, squeeze, fill, clearance, mating finish, installation method, motion, pressure cycles and temperature cycles. Define allowable leakage, dimensional change, hardness change and retained mechanical performance as appropriate. A coupon surviving immersion does not prove extrusion resistance or reliable dynamic sealing.

Include outdoor/ozone exposure, storage duration and cleaning in the requirements. Obtain current handling instructions for the actual raw polymer, compounding chemicals and finished product; these are different supplied states. Preserve compound and batch traceability through molding, cure, inspection and assembly.

Separate informative typical data, contractual acceptance limits and qualified service results. Review substitutions against the complete material, geometry and exposure requirements. A black rubber part with matching hardness is not sufficient evidence that it reproduces the original NBR compound.

## Related reference

[Material selection through production](../grades-tempers-and-conditions.md)