Oil seals—also known as shaft seals or rotary seals—are essential components in countless industrial systems. Whether in automotive gearboxes, hydraulic pumps, or food-processing equipment, choosing the right oil seal can be the difference between long-term performance and costly downtime.

At DXTSEALS, we specialize in high-performance sealing solutions, and we’ve outlined five key indicators to help you make the best oil seal choice for your application.

🔑 1. Operating Temperature Range

Temperature is one of the most critical factors affecting oil seal performance. Choosing the wrong material can lead to premature hardening, cracking, or deformation.

Common material guidelines:

• NBR (Nitrile): -40°C to +120°C — great for general use

• FKM (Viton®): -20°C to +200°C — ideal for high-temperature environments

• Silicone: -60°C to +200°C — suitable for both high and low extremes

• PTFE: up to 260°C — best for extreme heat and chemical resistance

➡️ Tip from DXTSEALS: Always match the seal material to your system’s maximum sustained temperature.

💧 2. Media Compatibility (Oil, Grease, Water, Chemicals)

Oil seals must resist degradation from the fluids they contain or exclude. A mismatch between material and medium can lead to swelling, shrinkage, or chemical breakdown.

Typical scenarios:

• Hydraulic oil: NBR or HNBR

• Aggressive fuels or solvents: FKM or PTFE

• Food-grade oils or water: Silicone or FDA-compliant materials

➡️ DXTSEALS insight: Provide us with fluid specifications and we’ll help you choose the optimal elastomer or composite.

⚙️ 3. Shaft Speed and Pressure

High rotational speed or pressure can generate excess heat and distort seal lips, reducing life span.

General sealing guidance:

• Standard oil seals: up to 5,000 RPM

• High-speed applications: require PTFE or spring-loaded seals

• Pressurized systems (>0.5 bar): may need pressure-resistant designs or back-up rings

➡️ DXTSEALS recommendation: For dynamic applications, CNC-precision sealing edges and optimized lip geometries improve sealing performance at speed.

🧱 4. Housing and Shaft Material & Surface Finish

The oil seal interacts constantly with the shaft surface. To maintain an effective seal:

• Surface roughness (Ra): should be 0.2–0.8 μm

• No grooves or scratches should be present on the shaft

• Hardness difference between seal lip and shaft prevents mutual wear

Also, ensure proper alignment and avoid shaft eccentricity.

➡️ Pro tip: DXTSEALS can manufacture seals based on custom shaft/housing dimensions for perfect fit and function.

🛠️ 5. Seal Type & Design Configuration

Not all seals are created equal. Different applications demand different sealing structures: