What Do the Numbers and Letters on Oil Seals Mean?

Number of hits：1522024-08-21 09:43:51　

　　Oil seals play a crucial role in preventing the leakage of lubricants and the ingress of contaminants. Understanding the markings on oil seals is essential for selecting the right seal for specific applications. These markings typically include numbers, letters, and combinations of both, each providing valuable information about the seal’s dimensions, material, and type.

　　1. Dimensions: The Numbers

　　The numbers on an oil seal usually indicate its dimensions, specifically the inner diameter (ID), outer diameter (OD), and width. For example, a seal marked “38-62-10” means it has an inner diameter of 38mm, an outer diameter of 62mm, and a width of 10mm. These measurements are critical for ensuring a proper fit and effective sealing.

　　2. Material: The Letters

　　Letters on oil seals denote the material from which the seal is made. Common materials include:

　　NBR (Nitrile Rubber): Known for its excellent resistance to oil and grease.

　　FKM (Fluoroelastomer): Offers high-temperature resistance and chemical stability.

　　PTFE (Polytetrafluoroethylene): Known for its low friction and high resistance to chemicals and heat.

　　Selecting the right material is vital for the seal’s performance and longevity, especially in demanding environments.

　　3. Type: The Combinations

　　Combinations of letters often indicate the type and design of the oil seal. For instance:

　　TC: A double-lip seal with a garter spring, commonly used for shaft sealing.

　　SC: A single-lip seal, typically used for bore sealing.

　　VC: A seal without a metal case, often used in applications where space is limited.

　　In addition to the primary markings, oil seals may have other codes or symbols indicating manufacturer details, batch numbers, or special features like dust lips or reinforced structures. These additional markings provide further assurance of the seal’s quality and traceability.

　　These combinations help identify the seal’s specific design features and intended use, ensuring optimal performance in various applications.