M5x75 Viton O-Ring 75A, 75 mm ID 85 mm OD - Pack of 25

In this review the focus is on a simple, durable sealing part: the M5x75 Viton O-Ring pack of 25. This review is for technicians, DIY mechanics, and hobbyists who need a reliable O-ring that resists fuels and many chemicals while surviving wide temperature swings. The single biggest reason to buy is material performance: made from Viton fluorocarbon with a 75A durometer, these O-rings deliver a firm, resilient seal that keeps thread protectors and small hydraulic or carburetor interfaces secure under real working conditions.

Key Features

• Material: Viton (fluorocarbon elastomer) provides strong resistance to fuels, oils, and many chemicals for longer service life.
• Hardness: The 75A durometer balances flexibility and firmness so the O-ring compresses to seal while resisting extrusion in moderate pressure applications.
• Temperature range: Rated for a wide operating range so it holds seals from cold starts to sustained high-heat environments.
• Round cross-section: The classic round profile forms an effective seal between overlapping cylindrical surfaces and threaded protectors.
• Dimensions: 75 mm ID and 85 mm OD with a 5 mm width fit a variety of metric threaded barrels and small housings where that size is required.
• Bulk pack: Supplied as a pack of 25 which is convenient for maintenance shops and repeat repairs where small parts are consumed frequently.

Who It's For

This O-ring pack is best for maintenance crews, motorbike or small-engine enthusiasts, and precision hobbyists who work with metric-threaded barrels, carburetor seats, or small hydraulic fittings and need chemical and fuel resistance. It is also suited to applications where thread protectors must stay in place and occasional exposure to fuels or aromatic hydrocarbons occurs.

Those who should look elsewhere include users requiring compatibility with strong alkalis, ammonia gas, or glycol-based brake fluids, since Viton can be vulnerable to those substances. If extreme low-temperature flexibility below the listed range is essential, a silicone or fluorosilicone alternative may be preferable.

Pros & Cons

Pros

• Excellent resistance to fuels and many chemicals thanks to Viton construction, making it reliable in automotive and industrial exposures.
• Good sealing performance and fit noted by customers for threaded barrels and carburetor seat seals.
• Wide usable temperature window so the same part can be used across varied environments.
• Pack of 25 offers value for maintenance use and repeat replacements.

Cons

• Not compatible with certain chemicals like low molecular organic acids, ammonia, and some brake fluids, which limits use in those specific systems.
• The listed high-temperature rating may vary with exposure time and aggressive media, so long-term use at top temperatures requires caution.

Specifications

Material	Viton (fluorocarbon elastomer)
Durometer	75A
Cross-section	Round
Inner Diameter (ID)	75 mm
Outer Diameter (OD)	85 mm
Width / Cross-section diameter	5 mm
Pack quantity	25 pieces

Our Verdict

The M5x75 Viton O-Ring pack is a practical, cost-effective choice for anyone who needs a durable seal that tolerates fuels and many chemicals while operating across a wide temperature range. It is particularly good value for maintenance shops and hobbyists who fit metric-threaded barrels or carburetor seals and want consistent performance from a trusted elastomer.

Frequently Asked Questions

Will these O-rings resist gasoline and hydraulic oil?
Yes; Viton offers good resistance to non-flammable hydraulic fuels, aromatic and aliphatic hydrocarbons, and most common automotive oils.

Do these O-rings fit Springfield threaded barrels or similar parts?
Customers report a good fit on several 10 mm auto Springfield threaded barrels and similar metric-threaded components when dimensions match.

Are they suitable for high vacuum or steam applications?
They perform well in high vacuum environments but are vulnerable to super-heated steam and certain chemicals, so avoid continuous exposure to aggressive media.