Synertech Stock
MP rotating shaft oil seals
A rotating shaft MP oil seal is a type of radial shaft seal that features a dust lip in addition to the main sealing lip, and is suitable for applications with pressures up to 0.5 bar (0.05 MPa).
Product codes
Details
The MP series rotary shaft seals, known on the market as metal-cased oil seals with dust lip or Type MP, are double-lip dynamic seals designed for the retention of fluid oils and greases. The profile combines an exposed "L"-shaped outer metal reinforcement, precision-ground, with a double-lip system: a main lip preloaded by a garter spring for internal fluid sealing and a second auxiliary front lip without a spring. This configuration ensures high mechanical locking within the housing and protects the system against abrasive external contaminants.
Type MP / WC Standard
Double-lip profile, with a spring-loaded main sealing lip and an auxiliary dust lip without a spring, with an exposed ground metal outer diameter.
Type MP Special
Variant with increased metal insert thickness or modified dust-lip geometries for highly contaminated applications or applications characterized by strong radial vibrations.
Materials and operating conditions
| Material / Compound | Peripheral speed | Temperature | Max pressure |
|---|---|---|---|
| NBR Nitrile rubber 70 / 80 ShA |
Up to 12.0 m/s Up to 0.5 m/s in low-speed applications |
−30 / +100 °C | 0.05 MPa Standard atmospheric pressure |
| FKM Fluoroelastomer / Viton |
Up to 35.0 m/s | −20 / +200 °C | — |
Metal structure
Mineral hydraulic oils, fluid gear lubricating oils, mineral and synthetic greases, water, mud and environmental dust.
Main features
Ground metal outer diameter
The exposed outer steel surface is mechanically press-fitted into the housing with precise diametrical interference. The metal-to-metal fit ensures high flatness and stable structural locking within the housing.
Double-lip protective action
The main lip, supported by the spring, ensures lubricant retention inside the housing, while the second auxiliary lip intercepts environmental contaminants such as dust, water splashes and pollen before they reach the primary dynamic sealing area.
Grease cavity
The space between the main lip and the dust lip is filled with lubricating grease during installation. This reduces friction on the auxiliary lip and helps trap the finest abrasive particles.
Advantages of the MP profile
Torsional stability
The press-fitted metal casing limits axial movement and elastic rebound during installation and counteracts the risk of ejection caused by vibrations or mechanical shocks.
Extended service life
The dust lip prevents external abrasive particles from penetrating beneath the main lip, reducing the risk of premature scoring on the rotating shaft diameter.
Heat transfer
Direct metal-to-metal contact between the oil seal's outer casing and the cast-iron or steel housing promotes dissipation of the heat generated by friction between the dynamic lip and the shaft.
Typical applications
- Housings and bearing seats exposed to the external environment in industrial gearboxes and heavy-duty geared motors
- Transmissions, power take-offs (PTO) and wheel hubs for agricultural machinery
- Crankshafts, camshafts, wheel hubs and differentials in the automotive, truck and special-vehicle sectors
- Hydraulic pumps, centrifugal pumps, fans and positive displacement compressors operating in dusty environments
- Drive axles and rigid angle drives exposed to high mechanical loads in earthmoving applications
International standards
Construction dimensions, geometric tolerances and installation dimensions in compliance with DIN 3760 Form BS and ISO 6194-1 Type 2C standards, corresponding to the universal WC / BC / AS-P profile.
Available configurations
Type MP Standard
Traditional configuration for general heavy-duty mechanical applications exposed to the external environment. It is ideally suited to stable housings machined in cast iron or steel, providing protection against dust and moisture at competitive cost.
Type MP Premium
Specific configuration for high-speed shafts up to 35 m/s or operating at high temperatures in contact with aggressive synthetic oils and in highly contaminated outdoor environments. The stainless-steel casing counteracts oxidation, while the fluoroelastomer withstands synthetic lubricants.
Market equivalents
| Manufacturer | Type MP Standard - NBR | Type MP Premium - FKM / Viton |
|---|---|---|
| Net Seals | Metal Oil Seal Series with Dust Lip WC / MP | Viton Metal Oil Seal Series WC / MP FKM |
| Freudenberg (Simrit) | Simmerring® BS / 827S SL Profile | Simmerring® BS FKM Profile |
| Parker Prädifa | SBL / BC Profile | SBL (FKM) Profile |
| Dichtomatik | WC Profile | WC FKM Profile |
| Kastas Sealing Technologies | K28 Metal Profile | — |
| Corteco | Type MP External Metal Oil Seal Series with Dust Lip | — |
| SKF | — | Viton metal-cased seals with auxiliary lip (CRWA5) |