M1.78x36.27 Viton O-Ring 75A - Pack of 100 Mr O-Rings

In this review the M1.78x36.27 Viton O-Ring is presented as a practical, no-nonsense sealing solution for technicians and hobbyists who need reliable resistance to fuels and many chemicals. The bottom line: this pack of 100 O-rings offers consistent dimensions and a durable Viton compound that works across a wide temperature range, making it a smart buy for repetitive replacement tasks or for applications where chemical compatibility matters.

Key Features

• Material: Made from Viton (fluorocarbon elastomer), the compound provides strong resistance to fuels and many aggressive chemicals so seals last longer in contact with oils and aromatic hydrocarbons.
• Hardness: A 75A durometer gives a balance of resilience and compressive strength suitable for static seals and many dynamic low-speed applications.
• Cross-section: The round cross-section creates a dependable seal between overlapping cylindrical surfaces, useful for threaded barrel protection and simple shaft seals.
• Temperature range: Rated for a broad working range, the material performs from below freezing to elevated temperatures, supporting both cold starts and hot operating conditions.
• Pack size: Supplied as a pack of 100, it reduces downtime and cost per seal for maintenance teams and owners who replace rings frequently.

Who It's For

This O-ring is aimed at mechanics, hobbyists, and maintenance technicians who need a small, consistent metric seal for hydraulics, fittings, threaded barrel protection, or carburetor seats. The chemical resistance and temperature tolerance make it a good fit for non-flammable hydraulic fuels, silicone oil, and many hydrocarbons.

Those who should look elsewhere include users who require full compatibility with strong alkalies, ammonia gas, glycol-based brake fluids, or continuous super-heated steam exposure; Viton is vulnerable to those media, so select a different elastomer for those specific services.

Pros & Cons

Pros

• Good chemical and fuel resistance thanks to Viton composition, so seals hold up in many service fluids.
• Balanced 75A durometer delivers reliable sealing without being overly stiff for most static and low-speed uses.
• Consistent metric sizing (36.27 mm ID, 39.83 mm OD, 1.78 mm width) and pack of 100 quantity make inventory and replacements easy.

Cons

• Not compatible with some chemicals such as strong alkalis, ammonia, or glycol-based brake fluids, so it is not universal.
• The hardness and material are not ideal for high-speed dynamic rotary seals where specialized compounds are required.

Specifications

Our Verdict

The M1.78x36.27 Viton O-Ring is a practical, cost-effective choice for routine sealing and protective needs where chemical and temperature resistance matter. Buy it if you need consistent metric O-rings for threaded barrels, carburetor seats, or general maintenance; avoid it only when your application involves known Viton incompatibilities or demanding high-speed rotary sealing.

Frequently Asked Questions

Are these O-rings compatible with gasoline and many oils?
Yes. Viton is resistant to many fuels and aromatic and aliphatic hydrocarbons, making these suitable for gasoline and many oils.

What temperature range do they support?
The rings are usable across a broad range from below freezing to elevated temperatures appropriate for most automotive and industrial applications.

How many rings come per pack?
This listing supplies a pack of 100 O-rings, which is convenient for repeated maintenance or stocking spares.