Do Metric o-ring set, NBR seals resist common automotive oils and fuels at 70 Shore hardness?

Metric o-ring set, NBR: Yes . NBR (nitrile rubber) at 70 Shore A is commonly used in automotive applications and generally offers good resistance to many common automotive oils, fuels, hydraulic fluids and greases. It performs well against petroleum-based oils and fuels, engine and transmission oils, and most lubricants used in vehicles. Limitations: NBR is less resistant to aromatic hydrocarbons (e.g., toluene, xylene), some fuel additives, and certain aggressive chemicals (strong acids, ketones like acetone). It also degrades faster at sustained high temperatures (typically above ~100â120Â°C) and with prolonged exposure to fuel blends containing ethanol or methanol compared with some other elastomers (e.g., FKM/Viton, EPDM for hot water/steam). Conclusion: For general automotive oil and fuel exposure under typical temperatures and service conditions, Metric o-ring set, NBR (70 Shore) is suitable. For continuous high-temperature service, aggressive solvents, or high-ethanol fuels, consider a more resistant material.

Can Metric o-ring set, NBR be used in food-contact applications at 70 Shore hardness?

Metric o-ring set, NBR: NBR (nitrile butadiene rubber) is commonly used for general-purpose seals but is not inherently food-grade. Whether it can be used in food-contact applications at 70 Shore hardness depends on specific formulation and approvals. You must confirm the material has relevant food-contact certifications (e.g., FDA 21 CFR 177.2600 for the U.S., EU Regulation EC 1935/2004/Reg. 10/2011) and that additives, curing agents and fillers are food-safe. Also verify suitability for the food type, temperature, and any cleaning/sanitation chemicals; NBR has limited resistance to hot water, steam and certain detergents. Without explicit food-grade certification from the supplier/manufacturer, do not use Metric o-ring set, NBR for food-contact applications.

Are Metric o-ring set, NBR suitable for dynamic sealing applications at 70 Shore hardness?

Metric o-ring set, NBR. suitability for dynamic sealing at 70 Shore Yes, Metric o-ring set, NBR with 70 Shore hardness can be used for some dynamic sealing applications, but suitability depends on the specific operating conditions. Key points to consider: - Material properties: NBR (nitrile) offers good resistance to mineral oils, greases and fuels, and decent mechanical strength. It performs well in temperatures roughly between -30Â°C and +100Â°C (short excursions possible), and has good abrasion resistance for many dynamic uses. - Hardness implications: 70 Shore A is a common hardness for o-rings used in both static and light-to-moderate dynamic applications. It provides a good balance of resilience and wear resistance; softer compounds (e.g., 60A) seal easier at low compression, while harder ones (>70A) handle extrusion and shear better. - Dynamic application limits: - Suitable for low-to-moderate reciprocating or rotary motion with moderate surface speeds, low pressure differentials, and good lubrication. - Not ideal for high-speed rotation, high-frequency reciprocation, high pressures without proper support (back-up rings), or where aggressive chemicals or extreme temperatures occur. - Friction and wear increase with hardness; 70A may cause higher friction than softer grades, potentially increasing heat and wear in tight-tolerance dynamic interfaces. - Installation and design recommendations: - Ensure proper surface finish, lubrication and compatible counterface materials to minimize wear. - Use correct gland design and clearance; consider anti-extrusion backup rings for higher pressures. - Check compression set and aging for expected service life; replace periodically in critical applications. - Test under real operating conditions when possible. Conclusion: Metric o-ring set, NBR at 70 Shore is acceptable for many light-to-moderate dynamic sealing tasks (especially oil/grease environments) but may be unsuitable for high-speed, high-pressure, chemically aggressive, or extreme-temperature applications. Evaluate operating parameters and perform application-specific testing.