TC TG Oil Seal Skeleton FKM Rubber Framework Double Lip Oil Sealing Ring 19-30mm

Measure three dimensions on the housing or the old seal: the inner diameter (ID, which matches the shaft diameter), the outer diameter (OD, which matches the housing bore), and the depth (axial width of the housing recess). These correspond directly to the Inner φ × Outer φ × Depth format used in the variant selector. If the old seal is still in place, a digital caliper gives the most accurate readings.

Both TC and TG designations describe double-lip skeleton oil seals with a metal-reinforced body. The primary difference lies in the secondary lip geometry and the degree of dust exclusion. TC seals have a secondary lip that contacts the shaft, while TG seals may have a non-contact or lightly loaded secondary lip. In practice, many suppliers use TC and TG interchangeably for this style. Check your OEM specification if the distinction is critical for your application.

FKM (fluoroelastic rubber, often referred to by the trade name Viton) offers significantly broader chemical resistance and a higher continuous temperature ceiling — typically up to 200 °C versus around 120 °C for standard NBR. If your application involves elevated operating temperatures, aggressive hydraulic fluids, fuels, or chemical exposure, FKM is the appropriate choice. NBR remains suitable for moderate-temperature, standard mineral-oil environments where cost is a priority.

TC/TG skeleton oil seals are designed for rotary shaft applications. Acceptable shaft surface speed depends on the specific seal size, lip geometry, lubrication conditions, and shaft surface finish (typically Ra 0.2–0.8 µm recommended). For high-speed applications, contact us with your shaft RPM and diameter so we can confirm suitability before you order.

Clean the housing bore and lightly lubricate the outer diameter of the seal with a compatible grease or oil. Use a flat press plate or a seal driver of the correct diameter to press the seal in squarely — never strike the seal face directly with a hammer. Press until the seal face is flush with or just below the housing face. Lightly lubricate the sealing lip before fitting the shaft to prevent dry-start damage.

FKM rubber has broad compatibility with most synthetic lubricants, including PAO-based synthetic engine oils, automatic transmission fluids (ATF), and many hydraulic fluids. It is generally not recommended for use with ketone-based solvents or certain ester-based fluids at elevated temperatures. If you are working with an unusual fluid, contact us with the fluid specification for confirmation.

For optimal sealing life, the shaft surface in the sealing zone should have a ground or polished finish with a roughness of Ra 0.2–0.8 µm (8–32 µin). The surface should be free of machining marks that run parallel to the shaft axis, as these can act as leak paths. A lead-in chamfer of approximately 15–20° at the shaft end helps guide the lip over the shaft without rolling or inverting it during installation.