Another benefit of using a bolt wedge is its strength and durability. The tapered shape of the bolt allows for a tight fit, which prevents the connected objects from shifting or coming loose
Figure 5: Shaft surface with and without lead marks
- chemical
Before installing the oil seal, it is essential that the oil seal, shaft and bore are not damaged. So, ensure that the surfaces the oil seal comes in contact with do not have any sharp points or burrs. The sealing lip is fragile, so any minor damage to it can cause leakage. Also, make sure the oil seal is clean. Even a small amount of dirt can cause a leak. Therefore, never use a pre-used oil seal for the assembly.
- One of the key advantages of porcelain spark plugs is their ability to withstand high temperatures. As the spark plug is located inside the combustion chamber, it is exposed to extreme heat during the ignition process. The ceramic material used in porcelain spark plugs can tolerate these high temperatures without degrading, ensuring reliable performance even under strenuous conditions.
Oil seals are made from multiple compounds and materials. Some of the oldest, still in use today, are leather and felt compounds. The trend in mass production, however, has seen a move towards synthetic rubber or elastomers. Nitrile is by far the most popular material but developments in PTFE have created a surge of interest in buyers needing seals for high-speed shaft rotation applications. Viton is taking over from the polyacrylic and silicone, as it works better in high-temperature applications and has a high-resistance to abrasion and harmful chemicals.
Want to learn more? Read “Oil Seals 101, Part 2”.
There are many different materials used to manufacture oil seals.


Just like pressure. The temperature capability of the oil seal shouldn’t be lesser than the temperature of the application. This is because any significant increase or even decrease in the temperature will affect the functionality of the oil seal. PTFE seals have the highest temperature capability, making them useful for applications that demand harsh weather and elements.
To prevent thelubricating oil from leaking outside even under high pressure of the oil.
Seals are classified by O.D. wall material, lip type, and whether they have a spring or not.
Major oil seals are specified in ISO 6194-1 and JIS B 2402-1.
Table 2 shows the common types of oil seals, while Table 3 shows the features of each type of oil seal.
Table 4 lists the JTEKT oil seal type codes and corresponding ISO and JIS standards.
3. The spring on the lip of the oil seal tends to provide support to the lip and prevents the lubricant from leaking outside and also prevents the entry of contaminants from outside.
Oil seals are available in an immense range of sizes, for shafts from a few millimetres to several metres. Once the shaft diameter, groove diameter (housing diameter) and groove width are known, selecting an appropriate oil seal is a simple task. An oil seal or its product description is usually associated with three dimensions, for example 6x15x4. These refer to the sizes of the hardware for which the oil seal is designed. In this example, this oil seal is suitable for: 6-mm shaft diameter x 15-mm groove diameter x 4-mm minimum groove width.
Shaft and Bore Tolerance

The simplest way is to know either the preferred manufacturers part number, the overall sizes of shaft diameter, housing diameter and bore depth, or use our brochure to establish the M Barnwell Services ordering reference. Many of the old traditional names of seal manufacturers have either changed or disappeared in this age of “acquisitions”. If no longer available, we will advise you and offer a suitable alternative seal, from stock whenever possible. If your concern is getting the right seals for the job, you will need to know something about the application as well as the overall sizes. If you have any doubts – contact us, we will help in your seal selection.