TC Skeleton Oil Seal — NBR Double Lip Rotary Shaft Seal, ID 46–50mm

Measure the shaft (inner diameter), the bore (outer diameter), and the housing depth (thickness). Match all three dimensions to the variant listed as ID × OD × Thickness. For example, a 50 × 72 × 10mm seal fits a 50mm (≈1.969") shaft in a 72mm (≈2.835") bore with a 10mm (≈3/8") housing depth. When in doubt, the shaft diameter (ID) is the most critical dimension — the seal must grip the shaft without leaking or spinning.

TC designates a skeleton-type seal with two sealing lips. The primary lip (with a garter spring) retains lubricant and maintains consistent radial contact as the shaft rotates. The secondary lip acts as a dust excluder, blocking contaminants from reaching the primary lip. This dual-barrier design generally outperforms single-lip (SC-type) seals in environments with dirt, moisture, or light debris — common in agricultural and outdoor equipment.

TC-type NBR oil seals are typically rated for low-to-moderate pressure applications — generally up to about 0.05 MPa (≈7 psi) of differential pressure. They are designed for dynamic shaft sealing in lubricated housings, not for high-pressure containment. If your application involves significant back-pressure, contact us to confirm suitability before ordering.

NBR (nitrile rubber) offers good resistance to petroleum-based oils, greases, and water splash — making it suitable for outdoor equipment like tractors, ATVs, and irrigation pumps that encounter rain and mud. It is generally not recommended for continuous submersion or exposure to aggressive chemicals such as ketones, esters, or concentrated acids. For those conditions, a FKM (Viton) seal is typically the better choice.

NBR TC oil seals typically operate in a temperature range of approximately -40°F to +250°F (-40°C to +120°C) and are generally suitable for shaft surface speeds up to about 4–6 m/s (≈800–1,200 RPM on a 50mm shaft). Actual performance limits depend on shaft surface finish (Ra ≤ 0.8 µm recommended), lubrication, and radial load. Contact us to confirm for your specific application.

These are metric-dimensioned seals. Many agricultural, automotive, and industrial machines sold in the US — including European and Asian imports — use metric shafts and bores. Always verify your shaft and bore measurements in millimeters before ordering. Common conversions for this size range: 46mm ≈ 1.811", 47mm ≈ 1.850", 48mm ≈ 1.890", 49mm ≈ 1.929", 50mm ≈ 1.969". If your equipment manual lists an imperial size, convert it and match to the closest variant.

1. Clean the bore and shaft thoroughly. 2. Lightly lubricate the seal lips with the fluid being sealed (gear oil, grease, etc.). 3. Press the seal squarely into the bore using a seal driver or a flat block — never hammer directly on the seal face or lip. 4. The open (spring) side of the seal typically faces the lubricant source. 5. Verify the seal sits flush or slightly below the bore face. 6. Protect the seal lips from sharp shaft edges or keyways during installation using a sleeve or tape.