O-ring material
Natural Rubber O-Rings
Natural rubber O-rings are the polyisoprene seal, the original elastomer, chosen where resilience, tear strength and abrasion resistance matter more than oil or weather resistance. No temperature range for natural rubber is on file here, and the compound sheet governs. Conquest supplies natural rubber O-rings in AS568 and metric sizes as a distributor, quoted in the compound the print names.
- Family
- Natural rubber (NR)
- Standard range
- No family range on file; the compound sheet governs
- Durometers
- 70 Shore A quoted as standard; other hardnesses by compound
- Standards
- ASTM D1418 NR; ASTM D2000 AA line callouts on specific compounds
- Product
- O-rings in AS568 and ISO 3601 sizes, quoted in the compound the print names
No family range is on file for this material; the compound datasheet and your application govern the final choice.
Larger and non-standard sizes: an O-ring beyond the molded size lists can be supplied as a spliced and vulcanized O-ring, which the maker joins from cord of the same compound. That page lists, family by family, which makers offer the compound as cord, and what to send for a quote.
What natural rubber is, and where it is chosen
Natural rubber is polyisoprene from the rubber tree, chosen for its resilience, tensile strength, tear strength and abrasion resistance at a low price. In seals it serves water, dilute acids and alkalis, alcohols and some ketones in glands that see impact, flexing or abrasive slurries, and it is the family behind many pump and valve parts in water service. The Parker® handbook lists it in its compatibility table without a text figure, so this page publishes no range; the compound sheet you order from governs.
Where natural rubber fails
Oils, greases, fuels and solvents swell it, ozone and sunlight crack it unless the compound carries protection, and heat ages it quickly. Where the medium is oil, nitrile; where the seal sits outdoors, EPDM; where heat is the problem, silicone or FKM. Natural rubber is the usual fit where the seal is beaten, flexed or abraded in water or air.
How to specify
Send the AS568 dash number or the inside diameter and cross-section, the durometer, the medium and the temperature, and whether the gland flexes or sees abrasion. The quote names the compound your print or your engineering specifies and sends its datasheet with the range it carries.
Sizes and forms we supply
All 369 AS568 sizes (349 general-purpose dash sizes plus the 20 boss-seal sizes) and the ISO 3601 metric series, in the durometers listed above; O-ring cord for rings spliced and vulcanized by the maker in odd diameters (static service only), where the compound is made as cord. The AS568 chart and the metric chart carry the dimensions, and the dash number guide explains the numbering.
Sources: No text temperature figure appears in ORD 5700 section 2.2 and no maker sheet is on file, so this page states none; Parker O-Ring Handbook ORD 5700, section 2.2 (read 2026-09-14) (compatibility table, family named only); Apple Rubber, O-ring material selection guide (what the family is and where it is used, qualitative), read 2026-09-14; ASTM D1418; ASTM D2000 (documents named, not reproduced).
Parker is a trademark of Parker Hannifin Corporation. No affiliation or endorsement is implied.
Reviewed by Grant Midstokke, Conquest Seal Corporation. Last updated September 2026. Material ranges are the published references named beside them; the compound datasheet and your application govern the final choice.
Frequently asked
What is natural rubber used for?
Seals and parts that are flexed, impacted or abraded in water or air, where resilience and tear strength matter and no oil is present.
What temperature range does natural rubber have?
No range is on file here, so this page states none; the compound datasheet governs.
Can natural rubber handle oil or sunlight?
No. Oils and fuels swell it and ozone cracks it; nitrile for oil, EPDM for weather.
Natural rubber or SBR?
Natural rubber is more resilient and stronger; SBR ages better and costs less. Neither handles oil or ozone.
Which durometer?
70 Shore A is the hardness quoted as standard; natural rubber is available softer than most families. The durometer guide covers the choice.
Related guides
Send the part number and the quantity for Natural Rubber
The AS568 dash number or the inside diameter and cross-section, the durometer, the quantity, the medium and temperature, and any specification the print names. A Conquest representative replies.
Request a quote