ISO/DIN Metric Rotary Shaft Seals
Durus metric oil seals are manufactured to ISO and DIN dimensional standards for European, Asian, and global industrial equipment. 1,507 standard sizes from 5mm to 470mm shaft diameter, available in NBR, Viton, Polyacrylate, and Silicone compounds.
What Is a Metric Oil Seal?
A metric oil seal is a rotary shaft seal dimensioned in millimeters according to ISO 6194 or DIN 3760 standards. The part number directly encodes the three primary dimensions: shaft diameter × bore diameter × width, separated by "X". For example, a 100X115X13 C seal measures 100mm shaft × 115mm bore × 13mm width with C-type construction.
Metric seals predominate on equipment built in Europe, Asia, and most countries outside North America. Common equipment using metric seals includes German gearboxes (SEW, Bauer, Lenze), Japanese pumps and motors (Mitsubishi, Sumitomo), and most global automotive transmissions.
Size Range Available
Durus metric oil seals cover the full industrial size range from miniature seals for small motors up to large-diameter seals for heavy process equipment:
| Shaft Diameter Range | Count | Typical Application |
|---|---|---|
| 5mm - 25mm | ~150 | Small motors, instruments, miniature actuators |
| 25mm - 50mm | ~280 | Pump shafts, small gearbox inputs, automotive seals |
| 50mm - 100mm | ~520 | Industrial gearboxes, hydraulic motors, agitators |
| 100mm - 200mm | ~410 | Heavy gearboxes, mixers, process equipment |
| 200mm - 470mm | ~147 | Large industrial machinery, mill equipment, marine applications |
Lip Configurations: Single vs Double Lip
Metric oil seals come in two primary lip configurations. The seal description identifies which is which:
- METRIC DBL LIP SEAL - Double lip with a primary sealing lip plus an auxiliary dust lip. Standard for industrial environments where dust and dirt may contact the seal
- METRIC SNGL LIP SEAL - Single primary lip only. For clean operating environments where dust exclusion is not required (e.g., interior gearboxes)
Browse by lip configuration: Double Lip Oil Seals · Single Lip Oil Seals
When to Choose Metric vs Inch
Always match the dimension system specified by the equipment manufacturer. Mixing inch and metric seals is not viable - even closely matched nominal sizes (1" vs 25mm) differ by 0.4mm, enough to cause immediate leakage. Equipment data plates, service manuals, and OEM part catalogs specify the correct dimension system. When in doubt, measure the existing seal in millimeters and match exact dimensions.
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Frequently Asked Questions
How do I read a metric oil seal part number?
Metric oil seal part numbers follow the format SHAFT × BORE × WIDTH followed by a type code. For example, 100X115X13 C means: 100mm shaft diameter, 115mm bore diameter, 13mm width, type C construction (full rubber coat). All dimensions are in millimeters. The type code at the end identifies the case and lip combination - C, B, BZ, SC, SB, VC, VB, etc.
What is the difference between a single lip and double lip metric oil seal?
A single lip seal has only the primary sealing lip - sufficient for clean environments inside sealed gearboxes. A double lip seal adds an auxiliary dust lip outboard of the primary lip, creating a small grease-packed cavity that excludes dust, dirt, and water. Double lip is standard for industrial machinery exposed to outside contamination; single lip is used where dust contact is not a concern.
Are metric oil seals available in Viton or Polyacrylate?
Yes. While most metric seals ship in NBR (Buna-N) as the industry default, Durus offers metric oil seals in Viton (FKM) for high-temperature applications up to 400°F, Polyacrylate (ACM) for EP gear oils and hot petroleum, and Silicone (VMQ) for wide temperature ranges. The product description specifies the compound. Viton metric seals are typically marked with a "V" suffix in the type code.
What are the most common metric oil seal sizes for industrial equipment?
The 50mm to 100mm shaft range covers the majority of industrial gearbox, pump, and motor applications - this range alone accounts for over 500 of our stocked metric sizes. Common standard combinations include 25×47×7, 30×52×7, 40×62×8, 50×72×8, 75×100×10, and 100×130×12. Texas Belting stocks the full ISO 6194 standard size range from 5mm up to 470mm shaft diameter.
Can a metric oil seal handle high pressure?
Standard radial shaft oil seals are designed for very low pressure applications - typically under 7 PSI (0.5 bar). Higher pressures will push the lip away from the shaft and cause leakage. For pressurized applications, specialized high-pressure seals or alternative sealing technologies (mechanical seals, lip seals with garter spring backup) are required. Contact Texas Belting at (888) 203-2358 to discuss high-pressure sealing applications.
Cross-reference from any CR, SKF, National, Federal-Mogul, or Timken part number. Houston, TX warehouse stocks the full Durus catalog with same-day shipping for in-stock items.
Call (888) 203-2358 or email sales@texasbelting.com with your existing part number, equipment make/model, or shaft and bore measurements.
