How to choose the right NBR seal?

NBR (nitrile rubber) seals are one of the most widely used sealing materials. Due to their good oil resistance, wear resistance and economy, they are widely used in the automotive, hydraulic, pneumatic, machinery manufacturing and other industries. But even if they are all NBR materials, the selection under different working conditions is also very particular. The following are some practical selection suggestions to help you choose NBR seals scientifically:

✅ 1. Choose according to the medium

NBR has excellent resistance to most mineral oils, lubricating oils, and hydraulic oils.

However, other materials should be carefully selected or considered when in contact with the following media:

❌ Ketones, esters, halogenated hydrocarbons (may cause swelling or decomposition)

✔ Can be used in water (below 60°C) and alcohols, but the formula needs to be carefully evaluated for long-term use

✅ 2. Select according to temperature range

Standard NBR temperature range: about -40°C to +120°C

High acrylonitrile NBR can enhance oil resistance but reduce low temperature resistance

If it is necessary to work at higher temperatures (>120°C), it is recommended to use fluororubber (FKM)

✅ 3. Select according to hardness and shape

Hardness selection (Shore A):

60~70A: suitable for low pressure or static sealing

80~90A: suitable for high pressure, high wear or dynamic sealing

Shape selection: Common ones include O-rings, oil seals, gaskets, lip seals, etc. The model and size should be selected according to the assembly structure

✅ 4. Pay attention to product processing technology and tolerance control

The mold accuracy and edge finish of the seal directly affect the sealing effect and service life

You should choose products from regular manufacturers with strict quality control and raw material traceability, such as Jinwoseal (Jinwo)

Tips: Four-step selection method

Clear working environment (temperature, pressure, medium)

Determine the seal type (static seal or dynamic seal)

Choose appropriate hardness and shape

Confirm that the size matches the assembly structure

Conclusion:

Although NBR seals are common, their selection cannot be ignored. Only by fully considering the working conditions and material matching can their high cost-effectiveness advantage be brought into play. Jinwoseal provides NBR sealing products of various specifications and formulas, and can provide customized services according to customer needs to help equipment operate stably and efficiently.