Oil Seals & Rotary Shaft Seals

Factory-direct radial lip seals for rotating shafts, gearboxes, pumps and hydraulic motors

Overview

Oil seals—also called rotary shaft seals, radial lip seals or rotary oil seals—are the primary sealing element protecting rotating machinery from lubricant loss and contaminant ingress. A typical oil seal consists of a metal reinforcing case, a flexible elastomer sealing lip and a garter spring that maintains constant lip contact against the shaft surface. Our oil seal range covers standard TG4/TC skeleton seals, split open-type seals for no-disassembly installation, J-type rubber seals, PTFE high-performance seals and K-type FKM seals for aggressive fluids. The TG4/TC profile is the most widely used rotary shaft seal geometry in industrial and automotive equipment. A metal outer case provides press-fit retention in the housing bore, while the rubber sealing lip is precision-molded with a defined contact angle against the shaft. A garter spring behind the lip compensates for material relaxation and thermal expansion, maintaining sealing contact across the rated temperature range. Standard TG4 seals are available from 20 mm to 210 mm inside diameter in NBR and FKM compounds, covering the majority of gearbox, pump, compressor and electric motor applications. Split oil seals solve the maintenance problem of replacing a seal without removing the shaft, pulley or bearing. The open-type construction allows the seal to be wrapped around the shaft and closed in the bore, eliminating hours of disassembly in large equipment. J-type oil seals are all-elastomer designs without a metal case, used in low-speed and low-pressure installations where flexibility and conformability matter more than structural rigidity. PTFE oil seals combine a stainless steel case with a PTFE sealing lip for extreme chemical resistance, high surface speeds and dry-running capability where conventional rubber would harden or swell. Our oil seals are manufactured to ISO 6194 and DIN 3760 dimensional standards with shore hardness from 70 to 90 Shore A. NBR compounds handle mineral oils, greases and water-glycol mixtures from -40°C to +120°C. FKM compounds extend service to +200°C with resistance to synthetic oils, fuels and aggressive chemicals. PTFE lips operate from -200°C to +260°C with near-universal chemical compatibility. Every seal can be supplied with custom inner diameter, outer diameter, width, lip design and spring material to match your drawing or OEM part number. How to choose an oil seal: start with shaft diameter, rotational speed and sealed fluid. For general rotary shafts in mineral oil or grease, a TG4/TC skeleton seal in NBR is the correct default. Move to FKM for temperatures above +120°C or aggressive fluids, PTFE for chemical or dry-running extremes, split seals when shaft removal is impractical, and J-type seals for low-speed worn housings. **Related guides:** [Oil Seal vs O-Ring: When to Use Each](/blog/oil-seal-vs-o-ring/) | [Oil Seal Types Complete Guide](/blog/oil-seal-types-complete-guide/)

Oil Seal Types

TG4 / TC Skeleton Oil Seals

Metal-cased rotary shaft lip seals with a garter spring. The industry standard for pumps, motors, gearboxes and axles. Available in NBR and FKM from 20 mm to 210 mm ID.

Best for: General rotary shafts 20–210 mm, gearboxes, pumps, electric motors

Split / Open-Type Oil Seals

Two-piece or hinged oil seals that install around the shaft without removing the assembly. Locking features maintain circumferential sealing after closure.

Best for: Large shafts and equipment where shaft removal is impractical

J-Type Skeletonless Oil Seals

All-rubber oil seals with a flexible J-shaped cross-section. Conform easily to worn or slightly out-of-round housings where metal-cased seals would leak.

Best for: Low-speed, low-pressure equipment and field retrofit

PTFE Oil Seals

Stainless steel case with a PTFE sealing lip for chemical, thermal and dry-running extremes. Common in process pumps, compressors and semiconductor equipment.

Best for: Chemical exposure, high surface speed, dry-running and wide temperature swings

K-Type FKM Oil Seals

FKM oil seals designed for aggressive fluids and elevated temperatures. The K profile offers reinforced lip geometry for high-performance automotive and chemical service.

Best for: Synthetic oils, fuels, acids and continuous operation above +150°C

TCV Medium-Pressure Oil Seals

Reinforced radial shaft seals rated for low to medium pressure, typically up to 0.3–0.5 MPa (3–5 bar), depending on size and speed. Common in hydraulic motors, rotary unions and swivels where a small positive housing pressure exists.

Best for: Hydraulic motors, rotary couplings and low-pressure spindles

VD / VS Dust Seals

Elastomer V-rings and axial dust seals that ride on the shaft surface to exclude dirt, water and abrasive particles from the primary seal zone.

Best for: Agricultural, mining and outdoor equipment requiring contamination exclusion

Y-Type Rubber Seal Rings

All-rubber Y-shaped rotary seals without a metal case. Used in low-speed shafts and legacy equipment where flexibility and conformability matter more than structural rigidity.

Best for: Low-speed shafts, vintage machinery, field retrofit

Z-Type Rubber Seal Rings

Z-profile rubber rotary seals with an asymmetric cross-section for unidirectional pressure service. Flexible all-elastomer design for worn or non-standard housings.

Best for: Single-direction rotating shafts, worn housings, agricultural equipment

EC End Caps

Elastomer end caps for shaft ends and housing covers. Simple push-on profile for static or low-speed rotary exclusion of dust and moisture.

Best for: Shaft end protection, bearing covers, idle shaft exclusion

Materials

Material	Properties	Best For
NBR (Nitrile)	-40°C to +120°C; excellent resistance to mineral oils, greases and water-glycol; economical	General industrial, gearboxes, pumps, standard hydraulic oils
FKM (Viton)	-20°C to +200°C; superior resistance to synthetic oils, fuels, acids and aromatics	High-temperature engines, chemical processing, aggressive fluids
PTFE	-200°C to +260°C; near-universal chemical resistance; low friction; dry-running capable	Chemical plants, cryogenics, semiconductor, high-speed shafts
HNBR	-40°C to +150°C; improved abrasion, ozone and sour-gas resistance versus standard NBR	Automotive, oilfield and applications with mechanical wear

Sizing

Oil seals are specified by inside diameter (shaft diameter) × outside diameter (bore diameter) × width (mm). Standard TG4/TC seals follow ISO 6194 / DIN 3760 size tables from 20 mm to 210 mm shaft diameter. Custom sizes, special widths and double-lip designs are manufactured from drawing or OEM sample.

TG4 / TC Standard

• 20–210 mm ID in standard tables
• Common widths: 7, 8, 10, 12 mm
• NBR and FKM lips

Split / J-Type / PTFE

• Custom ID and OD manufactured to drawing
• Special widths and lip geometries available
• MOQ from 1 piece for custom profiles

Frequently Asked Questions

What is the difference between TG4 and TC oil seals?

TG4 and TC are functionally identical double-lip metal-cased rotary shaft seals with a garter spring. TG4 is common in Asian and European supplier catalogs, while TC is the Parker/NAK equivalent. The dimensions, tolerances and installation requirements are the same.

When should I use a split oil seal instead of a TG4 seal?

Use a split seal when the cost of removing the shaft exceeds the cost premium of the split seal. Common scenarios include large pumps, mixers, turbines, paper machine rolls and any equipment where shaft removal requires crane rental or major disassembly.

How do I measure an oil seal for replacement?

Measure three dimensions: inside diameter (shaft diameter), outside diameter (bore diameter) and overall width. Use calipers on the metal case for OD and width, and measure the lip bore for ID. Provide the shaft material, rotational speed, operating temperature and sealed fluid so we can confirm material and lip design.

When should I choose FKM instead of NBR for an oil seal?

Choose FKM when continuous operating temperature exceeds +120°C, when the fluid contains synthetic esters, aromatics or aggressive additives, or when chemical compatibility is critical. NBR is the default for mineral oil and water-glycol mixtures below +120°C because it offers lower cost and better low-temperature flexibility.

What is the minimum order quantity for custom oil seals?

Standard sizes in NBR and FKM often ship from stock with no MOQ. Custom sizes, special compounds and PTFE seals start at one piece for prototypes and small-batch production. Contact us with your dimensions or OEM part number for a fast quotation.

Do you supply oil seals with stainless steel cases?

Yes. In addition to standard carbon steel cases, we offer 304 and 316 stainless steel cases for corrosive, food-grade and marine environments. PTFE oil seals are typically supplied with stainless steel cases as standard.

Can't find your seal profile in this list?

We manufacture many additional profiles including Y-type, Z-type, EC, YA, V-type backup rings, integral pistons (DK/DE/DP), buffer caps, cushion rings and solenoid valve gaskets. Send us a drawing or sample for a quotation — MOQ from 1 piece.