The TC metal skeleton oil seal is the
most widely used double lip skeleton oil seal in the industry . It consists of a rubber sealing body fully bonded to a metal reinforcing skeleton, a primary sealing lip with an integrated garter spring, and an additional dust lip . The metal skeleton provides structural strength and maintains shape under working conditions, while the double lip design provides both oil retention and contamination exclusion .
SANPING SEAL – Engineering Machinery High-End Seals – 17 Years Export Expertise
Product Overview
The TC skeleton oil seal is the representative form of skeleton oil seals . The “TC” designation indicates a rubber covered, double lip seal with a garter spring.
The TC metal skeleton oil seal has a relatively simple structure consisting of three main parts :
● Sealing Body (Rubber): The sealing主体 made of elastic rubber material, divided into the base, waist, lip, and sealing lip sections
● Metal Reinforcing Skeleton: Provides rigid support like reinforcement in concrete, helping the seal maintain its shape and tension
● Self-Tightening Garter Spring: Made of stainless steel wire, maintains constant radial pressure on the shaft
How It Works
In its free state, the TC seal’s inner diameter is smaller than the shaft diameter, creating an interference fit . When installed, the spring-loaded primary lip maintains constant radial pressure against the rotating shaft. The spring automatically compensates for lip wear over time, ensuring continued sealing performance .
Double Lip Design
The double lip configuration is the defining feature of the TC seal :
● Primary (Oil) Lip: Prevents internal oil or grease from leaking out; equipped with a garter spring to maintain sealing pressure
● Secondary (Dust) Lip: Keeps external contaminants like dust, mud, and water from entering the equipment
Metal Skeleton Construction
The metal skeleton (typically made of carbon steel or stainless steel) is vulcanized and bonded with the rubber sealing body . This integrated design provides:
● Structural rigidity for precise installation
● Dimensional stability under varying temperatures
● Resistance to deformation during operation
Specifications and Parameters
| Parameter |
NBR Material |
FKM/Viton Material |
| Structure |
Double lip with spring |
Double lip with spring |
| Skeleton Type |
Metal insert / Metal case |
Metal insert / Metal case |
| Hardness |
70-75 Shore A |
75 Shore A |
| Temperature Range |
-40°C to +120°C |
-20°C to +250°C |
| Working Pressure |
≤ 0.03 MPa (0.3 bar) |
≤ 0.03 MPa |
| Shaft Speed |
≤ 10 m/s |
≤ 25 m/s |
| Shaft Diameter Range |
5mm to 500mm+ |
5mm to 220mm |
| Color |
Black, Blue |
Brown, Red-brown |
Available Rubber Materials
● NBR (Nitrile Rubber) – Standard material for mineral oils, excellent oil resistance and abrasion resistance, temperature range -40°C to +120°C
● FKM (Viton/Fluororubber) – High temperature resistance up to 250°C, excellent chemical resistance for aggressive fluids
● Silicone (SI) – For extreme low-temperature or food-grade applications
● HNBR – Improved heat and abrasion resistance
Product Features
1. Metal Skeleton Reinforcement
The metal skeleton provides structural strength, helping the seal maintain its shape and tension under working conditions .
2. Double Lip Sealing
The primary lip seals oil inside while the secondary lip keeps contaminants out, providing complete protection for rotating shaft applications .
3. Rubber Covered Outer Diameter
The fully rubber-coated outer diameter ensures a reliable static seal even when housing bores have rough surfaces or minor damage .
4. Spring-Loaded Primary Lip
The garter spring maintains constant radial force on the shaft, automatically compensating for lip wear over time .
5. Excellent Contamination Resistance
The dust lip effectively blocks external dust, mud, water, and other contaminants from entering the equipment, making TC seals ideal for harsh environments .
6. Wide Material Selection
Available in NBR (standard), FKM (high temperature), and other materials to suit various operating conditions.
7. Broad Size Range
Available for shaft diameters from 5mm to over 500mm, with both metric and inch sizes .
Applications
TC metal skeleton oil seals are widely used across engineering machinery, automotive, and industrial equipment :
Construction Machinery:
● Excavators (final drives, engines, hydraulic pumps)
● Loaders (transmissions, axles, wheel hubs)
● Bulldozers (undercarriage, final drives)
● Forklifts, cranes, and hydraulic breakers
Automotive Applications:
● Engines (crankshaft, camshaft)
● Transmissions and differentials
● Wheel hubs and axles
Industrial Equipment:
● Gearboxes and reducers
● Pumps and compressors
● Electric motors
● Agricultural machinery
Other Applications:
● Injection molding machines
● Oil presses and hydraulic equipment
Product Advantages
1. Most Widely Used Oil Seal Type
TC is the industry standard skeleton oil seal, readily available in thousands of sizes and compatible with equipment from all major brands .
2. Effective Contamination Exclusion
The dust lip provides superior protection against external contaminants compared to single lip seals .
3. Structural Stability
The metal skeleton ensures the seal maintains its shape and sealing force even under demanding conditions.
4. Easy Installation
Standardized design allows for straightforward installation when proper procedures and tools are used.
Specification Format
TC oil seals are typically specified using the format:
Inner Diameter × Outer Diameter × Height (mm)
Why Choose SANPING SEAL?
17 Years of Export Expertise
Guangzhou Sanping Machinery Co., Ltd., established in 2009, has served customers across South Asia, Southeast Asia, Africa, South America, the Middle East, and Europe.
Specialized Focus
We concentrate exclusively on engineering machinery high-end seals, ensuring we understand your equipment applications better than general seal suppliers.
Quality Guarantee
Every order follows our two-step quality process: pre-production sample testing before mass production, and final inspection before shipment.
Frequently Asked Questions (FAQ)
Q: What does “TC” mean in oil seals?
A: TC indicates a rubber covered double lip oil seal with a garter spring. The rubber cover provides better static sealing, the double lip seals both oil and dirt, and the spring maintains radial pressure .
Q: What is the metal skeleton made of?
A: The metal skeleton is typically made of carbon steel or stainless steel, which is vulcanized and bonded with the rubber sealing body .
Q: What rubber materials are available?
A: We offer NBR (standard, -40°C to +120°C), FKM/Viton (high temperature, -20°C to +250°C) , silicone (low temperature), and HNBR (high durability).
Q: What is the working pressure limit?
A: TC seals are designed for low pressure applications up to 0.03 MPa (0.3 bar) .
Q: Is this seal suitable for dusty environments?
A: Yes, the double lip design (TC type) is specifically intended for applications where external dust is present .
Q: What is the difference between TC and SC oil seals?
A: TC has a rubber covered outer diameter and double lips (oil lip + dust lip). SC may have a metal outer diameter and only a single lip.
Q: What are your payment terms?
A: We accept T/T (bank transfer), L/C, MoneyGram, Western Union, and cash.