TC FKM Oil Seal for 35–50mm Shafts — Stop Leaks Before They Start
A weeping gearbox or a dripping pump shaft is more than a nuisance — it contaminates floors, accelerates bearing wear, and signals a seal that has given up. Mechanics, equipment rebuilders, and DIY machine restorers who work on gearboxes, motors, and agricultural drives need a rotary shaft seal that holds up to heat, oil, and continuous rotation without cracking or hardening prematurely. Standard NBR seals often fall short when fluid temperatures climb or when the equipment sits idle and then cycles through wide temperature swings.
These TC double-lip oil seals are made from FKM (fluoroelastic rubber), a material that generally withstands temperatures from approximately -20°C to +200°C (-4°F to +392°F) and resists petroleum oils, synthetic lubricants, hydraulic fluids, and many chemicals. Each seal follows the TC profile: a primary sealing lip with a garter spring for consistent radial load, plus a secondary dust/exclusion lip to keep contaminants out. Variants are specified as ID × OD × Thickness (mm) — for example, 40×60×8 means a 40mm shaft bore, 60mm housing bore, and 8mm groove depth. The range covers shaft IDs from 35mm to 50mm (≈1.38″ to 1.97″), outer diameters from 45mm to 80mm (≈1.77″ to 3.15″), and thicknesses of 5mm, 7mm, 8mm, 10mm, or 12mm depending on the size combination.
Typical applications include gearbox output shaft sealing to prevent gear oil leaks, electric motor end-shield sealing in pumps and compressors, and agricultural equipment driveshaft sealing where exposure to dirt, water, and wide temperature ranges demands a chemically resistant lip seal. The FKM compound also makes these seals a practical choice as replacement rotary shaft seals in industrial machinery where standard rubber seals have failed due to chemical attack or heat degradation.
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Compatibility Note: Variants are listed as ID × OD × Thickness (mm). Measure your shaft OD (= seal ID), housing bore (= seal OD), and groove depth (= seal thickness) before ordering. To convert inches to mm, multiply by 25.4. If your size is not listed, contact us.
✅ Key Features of These TC FKM Rotary Shaft Oil Seals
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🌡️FKM Fluoroelastic Compound — Withstands temperatures typically from -20°C to +200°C (-4°F to +392°F), making these seals suitable for high-temperature gearbox and motor applications where standard NBR lip seals harden and crack.
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🔩TC Double-Lip Design — The primary garter-spring-loaded lip maintains consistent radial sealing force against the shaft, while the secondary exclusion lip blocks dirt, dust, and water ingress — a critical feature for agricultural and outdoor equipment shaft seals.
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🛢️Broad Chemical Resistance — FKM resists petroleum oils, PAO and ester-based synthetic lubricants, hydraulic fluids, fuels, and many industrial chemicals, reducing the risk of seal swell or degradation that causes rotary shaft seal leaks.
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📐Wide Size Selection — Shaft IDs from 35mm to 50mm (≈1.38″–1.97″), ODs from 45mm to 80mm, and thicknesses of 5–12mm cover a broad range of gearbox, motor, and pump shaft seal replacement needs in a single product listing.
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⚙️Garter Spring Retention — An internal garter spring maintains consistent lip contact pressure throughout the seal's service life, compensating for minor shaft runout and helping maintain an effective oil seal even as the lip wears gradually.
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🏭Drop-In Replacement Geometry — Dimensioned to standard TC oil seal profiles, these seals are generally interchangeable with OEM shaft seals of the same ID × OD × thickness, simplifying sourcing for equipment rebuilds and preventive maintenance.
📐 Technical Specifications — TC FKM Rotary Shaft Oil Seal
| Seal Type |
TC (Double Lip with Garter Spring) |
| Lip Material |
FKM (Fluoroelastic / Viton®-type) |
| Metal Case Material |
See variant options (typically carbon steel) |
| Shaft ID Range |
35mm–50mm (≈1.38″–1.97″) |
| Outer Diameter (OD) Range |
45mm–80mm (≈1.77″–3.15″) |
| Thickness Range |
5mm, 7mm, 8mm, 10mm, 12mm (varies by size) |
| Operating Temperature |
Typically -20°C to +200°C (-4°F to +392°F) |
| Max Shaft Speed |
Contact us to confirm for your specific size |
| Max Differential Pressure |
Generally up to ~0.3 bar (4.4 psi) |
| Compatible Fluids |
Petroleum oils, synthetic oils (PAO/ester), hydraulic fluids, fuels |
| Finish / Color |
See variant options |
| Quantity per Order |
1 piece per variant selected |
| Variant Format |
ID × OD × Thickness (all in mm) |
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Before ordering: Confirm your shaft OD, housing bore diameter, and groove depth. FKM is not recommended for use with ketones, concentrated esters, or certain brake fluids. If your application involves unusual fluids or pressures, contact us to confirm suitability.
❓ Frequently Asked Questions
How do I choose the right size TC oil seal?
Measure three dimensions: your shaft's outer diameter (this becomes the seal's ID), the bore diameter in the housing (this becomes the seal's OD), and the groove depth (this becomes the seal's thickness). The variant format is ID × OD × Thickness in mm. For example, a 40×60×8 seal fits a 40mm shaft in a 60mm bore with an 8mm groove. To convert from inches, multiply by 25.4 — e.g., a 1.575″ shaft ≈ 40mm, a 2.362″ bore ≈ 60mm.
What does FKM mean, and why does it matter for oil seals?
FKM (also marketed as Viton®) is a fluoroelastic rubber that generally withstands temperatures from about -20°C to +200°C (-4°F to +392°F) and resists petroleum oils, hydraulic fluids, fuels, and many chemicals far better than standard NBR rubber seals. If your equipment runs hot or uses synthetic lubricants, FKM is typically the right choice over NBR.
Can these oil seals be used outdoors or in wet environments?
Yes. The TC design features a secondary dust lip in addition to the primary sealing lip, which helps exclude water, dirt, and contaminants. FKM also offers good resistance to weathering and ozone, making it suitable for outdoor machinery and equipment exposed to moisture — including agricultural drives and garden equipment.
What is the pressure rating of these shaft seals?
TC-type rotary shaft seals are generally designed for low-pressure dynamic sealing — typically up to about 0.3 bar (4.4 psi) of differential pressure. They are not intended for high-pressure hydraulic circuits. For the specific pressure rating of your chosen size, please contact us to confirm.
Are these seals compatible with synthetic oils and hydraulic fluids?
FKM seals are generally compatible with mineral oils, synthetic oils (PAO, ester-based), hydraulic fluids, fuels, and many aggressive chemicals. They are not recommended for use with ketones, esters at high concentrations, or certain brake fluids. When in doubt, verify fluid compatibility with your fluid supplier before installation.
How do I install a TC oil seal correctly?
Clean the housing bore and shaft. Lightly lubricate the seal lip with the fluid being sealed. Press the seal squarely into the bore using a seal driver or a flat plate — never hammer directly on the seal face. Ensure the seal is flush or slightly below the housing face. Check that the garter spring is seated in the lip groove before installation.
What shaft surface finish is recommended for reliable sealing?
For reliable sealing, the shaft surface in the sealing zone should generally have a finish of Ra 0.2–0.8 µm (8–32 µin). Rough or scored shafts will cause premature seal wear and leakage. A hardness of HRC 45–60 in the contact zone is typically recommended to minimize shaft wear over time.
Which equipment types commonly use these TC FKM oil seals?
These seals are commonly used in gearboxes, electric motors, pumps, agricultural equipment, small engines, compressors, and industrial machinery where a 35–50mm shaft passes through a housing and must be sealed against oil or grease leakage. They are a practical drop-in replacement for OEM shaft seals of the same dimensions.
🛒 Select your size (ID × OD × Thickness) above, then add to cart — ships from our US warehouse.
