The cost of new spark plugs can range from as low as $2 to as high as $20 per plug. Cheaper spark plugs are often made of basic materials and may not last as long as more expensive options. On the other hand, high-quality spark plugs are made of premium materials such as platinum or iridium, which can resist wear and corrosion better than cheaper materials.
Figure 1: Types of sealing devices

oil seal 50 * 72 * 10.
Other important factors are ensuring the hardness and roughness of the shaft are correct. A shaft hardness of HRC 45 is recommended for a rubber sealing lip, with a roughness of Ra 0.4-0.8. A higher shaft hardness of HRC 60 and shaft roughness of Ra 0.1-0.4 is recommended for a PTFE lip.
After the oil seal is positioned in the groove, apply even pressure to the oil seal using a seal driver or a similar tool. This will help to seat the oil seal firmly in the groove and prevent it from moving during use. Make sure to apply the pressure evenly and gently, as applying too much force can damage the oil seal or cause it to deform.
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Rubber type
What Are Oil Seals?