Engine Oil Resistant O-Rings
Compatibility ratings for 7 O-ring materials in Engine Oil service
Engine Oil (Oils & Lubricants) compatibility with the seven most common O-ring elastomers, rated on the standard A/B/C/D scale: A = excellent, B = good, C = fair, D = not recommended. This data also appears in our interactive chemical compatibility chart and is available machine-readable at /api/chemicals.json.
| Material | Rating | Guidance |
|---|---|---|
| NBR | A | excellent — recommended for continuous service |
| FKM | A | excellent — recommended for continuous service |
| EPDM | D | not recommended — rapid degradation expected |
| VMQ | C | fair — conditional use, verify with testing |
| PTFE | A | excellent — recommended for continuous service |
| FFKM | A | excellent — recommended for continuous service |
| HNBR | A | excellent — recommended for continuous service |
Why These Ratings
- NBR (A) — documented strengths include “Mineral oils.”
- FKM (A) — documented strengths include “Mineral oils and greases.”
- EPDM (D) — documented weaknesses include “Mineral oils.”
- VMQ (C) — documented weaknesses include “Petroleum oils (general purpose).”
- PTFE (A) — documented strengths include “Fuels and oils.”
- FFKM (A) — documented strengths include “Fuels and oils.”
- HNBR (A) — documented strengths include “Mineral oils.”
Oils & LubricantsService: Concentration & Temperature Notes
Petroleum oils are the easiest service in this catalog for NBR, FKM, HNBR, PTFE and FFKM — all rate A. Two traps remain: EPDM, which swells severely and rates D across every oil row; and synthetic fluids, whose additive chemistry differs from mineral oil — our hydraulic-synthetic row shows EPDM improving to C while NBR drops to B versus mineral hydraulic oil.
Recommended
- NBR O-rings (A)
- FKM O-rings (A)
- PTFE O-rings (A)
- FFKM O-rings (A)
- HNBR O-rings (A)
Use With Caution
- VMQ O-rings (C)
Avoid
- EPDM (D)
Related Chemicals (Oils & Lubricants)
Frequently Asked Questions
Is Engine Oil compatible with FKM (Viton) O-rings?
FKM is rated A for Engine Oil: excellent — recommended for continuous service. Ratings are general guidelines; concentration, temperature and exposure time all affect real-world compatibility, so validate critical applications with ASTM D471 immersion testing.
Is Engine Oil compatible with NBR (nitrile) O-rings?
NBR is rated A for Engine Oil: excellent — recommended for continuous service. NBR is the lowest-cost elastomer, so when it earns an A or B rating it is usually the economical default; when it rates C or D, do not substitute it for a higher-rated material to save cost.
Can I use PTFE O-rings with Engine Oil?
PTFE is rated A for Engine Oil: excellent — recommended for continuous service. Remember that PTFE has no elastic memory — in demanding service it needs spring energization or an elastomer core (FEP/PFA encapsulation) to maintain sealing force.
What is the best O-ring material for Engine Oil?
NBR, FKM, PTFE, FFKM, HNBR are rated A (excellent) for Engine Oil in our compatibility data and are the recommended starting point for material selection. Final selection should also account for operating temperature, pressure and whether the seal is static or dynamic.
Can I use EPDM O-rings with Engine Oil?
EPDM is rated D for Engine Oil: not recommended — rapid degradation expected. Always confirm the specific fluid concentration and temperature before specifying EPDM for this service.
Need O-Rings for Engine Oil Service?
Send us your fluid, concentration and temperature — our engineers will confirm the right compound. MOQ 1 piece.