Overview
NBR (nitrile butadiene rubber) oil seals are oil-resistant sealing components used to retain lubricant and exclude contaminants in rotating and reciprocating equipment. NBR’s excellent resistance to petroleum oils, greases, and fuels — combined with good mechanical strength and low cost — makes it the standard elastomer for oil seals, O-rings, and hydraulic seals.
ORRO Manufacturing supplies NBR oil seals molded and machined to precise dimensions and durometers. We match the NBR compound to the fluid and temperature of your application and can produce bonded seals with metal or fabric reinforcement where a rigid mounting frame is required.
Material Properties
| Property | NBR (Nitrile) |
|---|---|
| Density (g/cm³) | 1.00 - 1.20 |
| Tensile Strength (MPa) | 10 - 20 |
| Hardness (Shore A) | 40 - 90 |
| Continuous Service Temperature (°C) | -40 to +120 |
| Compression Set (%) | 15 - 30 |
| Oil / Fuel Resistance | Excellent |
| Water Resistance | Good |
| Ozone / Weather Resistance | Poor |
Key Advantages
- Excellent Oil and Fuel Resistance: Withstands petroleum oils, greases, and hydraulic fluids.
- Good Mechanical Strength: High tensile and tear strength for dynamic sealing duty.
- Wide Temperature Range: Service from -40°C to +120°C.
- Low Compression Set: Maintains sealing force under sustained compression.
- Good Abrasion Resistance: Withstands sliding contact in rotating seals.
- Cost Effective: Economical choice for oil and grease sealing.
Typical Applications
Gearboxes and Motors
Rotary shaft seals that retain lubricant and exclude dust and moisture.
Hydraulic and Pneumatic Systems
Seals and O-rings for hydraulic fluids and pneumatic actuators.
Automotive and Industrial Machinery
Oil seals in engines, pumps, and rotating equipment.
Machining Capabilities
| Parameter | Capability |
|---|---|
| Tolerance | ±0.1 mm (dimensions), ±0.2 mm (profile) |
| Hardness Range | 40 - 90 Shore A |
| Size Range | 5 mm to 400 mm diameter |
| Key Processes | Compression molding, die cutting, CNC machining |
Application Case
Gearbox rotary oil seal, NBR — A gearbox manufacturer needed oil seals that would retain synthetic lubricant at 110°C while excluding dust in a dusty plant environment. ORRO supplied molded NBR seals in 70 Shore A with a bonded metal case, delivering 20,000 pieces in 15 days. The seals eliminated a recurring leak that had been occurring with a lower-grade rubber.
