Shaft Oil Seals come in different types and sizes to satisfy different applications, in order to determine the suitable size for the shaft oil seal you'll need the following specs:

1. Shaft Diameter (Inner Diameter – ID)

  • This is the diameter of the rotating shaft that the seal lip contacts.

  • It must match the seal’s inner diameter (ID) exactly for a proper fit and sealing pressure.

  • Measurement: Use a micrometer or vernier caliper to measure the shaft at the sealing point.

  • The shaft surface should be smooth and within tolerance (usually ±0.13 mm).

2. Bore Diameter (Outer Diameter – OD)

  • This is the diameter of the housing or bore where the oil seal will be pressed.

  • It corresponds to the outer diameter of the seal.

  • The OD ensures a tight, static fit between the seal body and the housing.

  • Measurement: Use a caliper to measure the bore in which the seal will be seated.

  • The fit is typically an interference fit to prevent leakage around the outer edge.

3. Width (Thickness)

  • This is the axial width or thickness of the seal body.

  • It must match the available space in the housing and ensure proper alignment with the shaft.

  • The width can also affect sealing pressure and stability.