- Family
- FEPM (tetrafluoroethylene-propylene)
- Standard range
- -9 C to 232 C (Parker® O-Ring Handbook ORD 5700)
- Durometers
- 70 Shore A quoted as standard; other hardnesses by compound
- Standards
- ASTM D1418 FEPM
- Product
- O-rings in AS568 and ISO 3601 sizes, quoted in the compound the print names
Service temperatures here are the family figures published in Parker O-Ring Handbook ORD 5700 §2.2.14; 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.
Aflas O-rings are made of FEPM (a tetrafluoroethylene-propylene copolymer), the material that covers sour gas, amines, steam and strong bases where FKM fails but FFKM is more than the job needs. The Parker O-Ring Handbook (ORD 5700 §2.2.14) rates FEPM from -9 C to 232 C, and it is poor in the cold; the compound sheet governs. Conquest supplies Aflas and other FEPM O-rings in AS568 and metric sizes. Greene Tweed's Fluoraz® is an FEPM-class line.
Aflas (FEPM) O-ring specifications
| Property | Value | Source |
|---|---|---|
| Temperature range | -9 C to 232 C | Parker ORD 5700 §2.2.14 |
| Durometers supplied | 70 Shore A quoted as standard; other hardnesses by compound | The compound sheet states the hardness |
| Material designation | FEPM under ASTM D1418 | ASTM naming |
| Strong against | Amines and amine-based corrosion inhibitors, sour gas, steam and hot water, strong bases, oils | Parker O-Ring Handbook ORD 5700; manufacturer literature |
| Weak against | Aromatic fuels and some solvents where FKM is better; low-temperature flexibility | Parker O-Ring Handbook ORD 5700 |
| Typical duty | Oilfield completions and downhole tools, chemical processing, automotive engine oils with amine additives, steam | Manufacturer literature |
| Related material | FFKM where the chemical list is broader still | Parker ORD 5700 |
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); and X-rings and backup rings in the same families. The AS568 chart and the metric chart carry the dimensions, and the dash number guide explains the numbering.
Aflas between FKM and FFKM
| Medium | Viton® (FKM) | Aflas (FEPM) | FFKM |
|---|---|---|---|
| Amines, amine-treated oils | Not recommended | Good | Excellent |
| Sour gas (hydrogen sulfide) | Limited | Good | Excellent |
| Steam and hot water | Poor in standard grades | Good | Excellent on steam grades |
| Strong bases | Limited | Good | Excellent |
| Aromatic fuels, chlorinated solvents | Excellent | Limited | Excellent |
| Ketones | Not recommended | Limited | Excellent |
| Cost | Moderate to high | Higher | Highest |
Typical applications
Downhole tools, packers and wellhead seals in sour-gas service; amine gas-treating units and corrosion-inhibitor injection systems in refineries and chemical plants; steam and hot-water service where oil is also present; engine oils formulated with amine additive packages; and process equipment handling strong bases, where FKM's chemistry runs out before FFKM's cost is justified.
The Viton page and the FFKM page cover the neighbors; the FFKM vs Viton comparison places Aflas between them, and the chemical compatibility guide covers the media.
Sources: AS568; ASTM D1418; ISO 3601; Parker O-Ring Handbook ORD 5700, section 2.2.14, read 2026-09-14.
Parker is a trademark of Parker Hannifin Corporation. Aflas is a trademark of AGC; Fluoraz is a trademark of Greene Tweed; Viton is a trademark of The Chemours Company. 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 temperature range does Aflas have?
The Parker O-Ring Handbook rates FEPM from -9 C to 232 C; the compound datasheet governs.
Aflas or FFKM for an amine service?
Aflas where the medium is amines, sour gas or steam and the compound sheet covers the temperature; FFKM where solvents or ketones are also present or the temperature is higher.
Is Aflas a brand or a material?
A trademark (AGC) for FEPM; other makers sell the same class under their own names.
Which durometer?
70 Shore A is quoted as standard, and other hardnesses are set by the compound; the harder grades serve high-pressure downhole service. See the durometer guide.
Related guides
Send the part number and the quantity for Aflas
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.
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