O-ring material
Polyacrylate O-Rings
Polyacrylate O-rings are the acrylic rubber (ACM) seal built for one job: hot petroleum oil loaded with the sulfur-bearing extreme-pressure additives that harden nitrile. The Parker® O-Ring Handbook rates the family from -21 C to 177 C, and Conquest supplies polyacrylate O-rings in AS568 and metric sizes as a distributor, quoted in the compound the print names.
- Family
- Polyacrylate (ACM)
- Standard range
- -21 C to 177 C (Parker O-Ring Handbook ORD 5700)
- Durometers
- By compound; the compound sheet states it
- Standards
- ASTM D1418 ACM; ASTM D2000 DH line callouts on specific compounds
- Product
- O-rings in AS568 and ISO 3601 sizes, quoted in the compound the print names
Ranges are the handbook family figures; 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 polyacrylate is, and where it is chosen
Polyacrylate is a copolymer of acrylic esters with a small cure-site monomer, and it resists oxygen, ozone and weather. Its reason for being is automatic transmission fluid and gear oil at the temperatures a gearbox reaches (Parker section 2.2.11). It holds up in hot mineral oil and dry heat, and automatic transmission and power-steering seals are its main use. The Parker handbook puts the family at -21 C to 177 C.
Where polyacrylate fails
Water, steam, glycols and alcohols attack it, and it is poor below about -21 C, so it is never a general-purpose seal. Its mechanical strength and compression set are below nitrile's, which keeps it out of demanding dynamic glands. Where the oil is hot, HNBR or FKM serves a wider range of media; where transmission or gear oil is the medium, polyacrylate is the usual fit. The ethylene-acrylic family covers similar oils with better cold flexibility.
How to specify
Send the AS568 dash number or the inside diameter and cross-section, the durometer, the oil by name, the temperature and any ASTM D2000 line callout the print carries. The quote names the compound your print or your engineering specifies and sends its datasheet.
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 AS568 sizes in millimeters carry the dimensions, and the dash number guide explains the numbering.
Sources: Parker O-Ring Handbook ORD 5700, section 2.2 (read 2026-09-14) (§2.2.11); Apple Rubber, Seal Design Guide, Polyacrylate page (qualitative), read 2026-09-27; ASTM D1418; ASTM D2000 (documents named, not reproduced); Parker O-Ring Handbook ORD 5700, page 2-10 (hardness guidance), read 2026-09-25; Parker O-Ring Handbook ORD 5700, section 2.2.11 resistance list and Table 2-2 (page 2-9), read 2026-09-27.
Parker is a trademark of Parker Hannifin Corporation. No affiliation or endorsement is implied.
Frequently asked
What is polyacrylate used for?
Seals in automatic transmissions, power steering and gearboxes running hot mineral oil.
What temperature range does polyacrylate have?
The Parker O-Ring Handbook rates ACM from -21 C to 177 C; the compound datasheet governs.
Can polyacrylate handle water or steam?
No. Water, steam, glycols and alcohols attack it; EPDM or a suitable FKM serves those.
Polyacrylate or ethylene-acrylic?
Both serve hot additive-laden oil. Ethylene-acrylic is more flexible in the cold; polyacrylate holds the top of the oil range. Name the medium and the temperature; the quote names the compound your print or your engineering specifies.
Which durometer?
The compound sheet states it; for most applications the Parker handbook puts the usual choice at 70 to 80 Shore A (ORD 5700, page 2-10). The durometer guide covers the choice.
Related guides
Orders are handled under Conquest Seal's AS9100D quality management system, whose certificate scope includes distribution.
Send the part number and the quantity for Polyacrylate
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. Quotes answered within one business day. A person answers (714) 632-9830, Pacific business hours.
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