Whole Series PTFE/NBR/FKM/Fabric Rotary Shaft Oil Seals

Oil seals are also known as rotary shaft seals. They are often called grease, fluid or dirt seals. They close spaces between stationary and moving components in mechanical equipment. They are used to help prevent lubricant escape. Oil seals stop harmful contaminants from entering machinery, particularly in severe environments. They are vital components of almost every type of machine and vehicle in operation. They protect all types of precision-constructed, close-fitting ball, sleeve and roller bearings.

Oil seals help prevent lubricants from escaping the bearings or a specific area in precision bearings.

In machine components, oil seals help prevent abrasives, corrosive moisture and other harmful contaminants from entering machinery. They also help stop mixture of two different mediums such as lubricating oil and water.

Rotary Shaft seals are produced by vulcanising an elastomer to a metal ring. This acts as a stiffener, and utilises a metal tensioning spring behind the sealing lip. Many other designs can be supplied. These include, High Pressure, Dual Spring and end caps. The most common elastomer used is Nitrile.

The seals conform to DIN 3760. Rubber types available are Nitrile, Viton ®, Silicone and EPDM.

The seals are used in a full range of equipment in the following industries:
• Automotive.
• Manufacturing.
• Off-highway.
• Oil refineries.
• Power transmission.

Example applications include:
• Industrial Pumps.
• Electric Motors.
• Compressors & Vacuum Pumps.
• Engine Seals.
• Agricultural Machinery Seals.
• Domestic Appliances

Lip Material
It is very important to take into account the environment in which the seal will operate when you are selecting the sealing element material. The most important factors are temperature, medium being sealed, pressure, and shaft speed.

Shaft and Bore Configurations Shaft MaterialSeals perform best on medium carbon steel or stainless steel shaft. Heat treatment or nitriding is especially recommended. To seal water at low surface velocities, stainless steel is more suitable.
The minimum hardness on the area where the sealing lip contacts the shaft should be 45 HRC. Where lubrications is doubtful, abrasive matter is present, or shaft speed is greater than 4m/sec, 55 HRC is preferred.
The shaft must be machined to the surface Roughness of Rt=1 to 4 micrometers (Ra=0.2 to 0.8 micrometers). In the areas of the contact surface, any rifling marks are not permitted.Shaft Tolerance   Configuration of the BoreThe leading corner of the bore should be chamfered and free of burrs. The inside corner of the bore should have a maximum radius of 0.047". The tolerances for the bore are shown below. Bore MaterialSteel and cast iron provide a good surface for both rubber O.D. and metal O.D. seals. For soft alloy (aluminum) bore, seals with rubber O.D. provide better sealing capacity than metal O.D.
The table below shows the recommended maximum bore roughness.
Shaft EccentricityTwo types of shaft eccentricity effect seal performance. They are dynamic runout (double dynamic eccentricity) and offset (shaft to bore misalignment or static eccentricity).

The accompanying graphs show tolerance levels for each type.Shaft Runout
Shaft Offset


We have the biggerst vulcanizing machine(4000T) and different kinds of seal moulds. So for the non standard oil seals, please do not hesitate to contact with us. The following is the the picture of our moulds.