Industrial Oil Seals, Wear Sleeves & End Caps
Durus manufactures rotary shaft oil seals, Durusleeve shaft repair sleeves, and metric end caps for industrial equipment. Four elastomer compounds (NBR, Viton FKM, Polyacrylate ACM, Silicone VMQ) covering 2,800+ standard inch and metric sizes - stocked in our Houston, TX warehouse for same-day shipping.
What Is a Rotary Shaft Oil Seal?
A rotary shaft oil seal - also called a lip seal, radial shaft seal, or grease seal - sits in a housing bore and rides against a rotating shaft. The flexible elastomer lip retains lubricant inside the equipment while excluding dust, dirt, and contaminants from the outside. Without functioning seals, gearboxes leak oil, bearings fail prematurely from contamination, and machinery requires costly unplanned maintenance.
Durus oil seals are specified by three dimensions: inner diameter (shaft size), outer diameter (bore size), and width. The complete part designation also includes a case type (A, B, C, F, or BZ) and a lip type (Standard, S, V, K, or D) which together describe the seal's construction.
Browse by Category
Material Selection at a Glance
Four elastomer compounds cover the full range of industrial sealing applications. Choose by operating temperature and the fluid being retained.
| Compound | Temperature Range | Best Compatibility | Avoid |
|---|---|---|---|
| NBR (Buna-N) - Nitrile | -40°F to 250°F | Mineral oils, hydraulic fluids, water, dilute acids | Aromatic fuels, hot oils above 250°F |
| Viton (FKM) - Fluorocarbon | -40°F to 400°F | Fuels, gasoline, synthetic oils, brake fluid, chemicals | Ketones, esters, amines |
| Polyacrylate (ACM) | -25°F to 300°F | EP lubricants, gear oils, ATF, hot petroleum oils | Water, glycol coolants, brake fluid |
| Silicone (VMQ) | -65°F to 350°F | Engine oil, dry running, food-grade applications | Gear oils with EP additives, gasoline |
See the full compound compatibility chart on individual product pages for a fluid-by-fluid breakdown.
How Durus Part Numbers Work
Durus uses a two-letter prefix system describing the case + lip combination:
| Prefix | Case | Lip | Description |
|---|---|---|---|
| TC | C (full rubber coat) | Standard | Most common - primary lip + auxiliary dust lip in a rubber-coated case |
| TB | B (bare metal) | Standard | Lead-in chamfer for easy install in hard housings, no dust lip |
| SC | C (full rubber coat) | S (single lip, no dust) | Single-lip variant of TC for clean, low-pressure applications |
| SB | B (bare metal) | S (single lip, no dust) | Single-lip metal-case version for clean applications |
| VB | B (bare metal) | V (no spring, no dust lip) | Grease and viscous fluid sealing without garter spring |
| KB | B (bare metal) | K (V-style + dust lip) | V-style sealing with added dust exclusion |
Browse by type: TC · TB · SC · SB · VB · SB2 · TB2
Frequently Asked Questions
How do I measure an oil seal for replacement?
Measure three dimensions: the outside diameter of the rotating shaft at the sealing location (inner diameter / shaft size), the inside diameter of the housing bore (outer diameter / bore size), and the depth of the seal cavity (width). For inch seals, dimensions are in decimals like 1.000" × 1.625" × 0.250". For metric seals, dimensions are in millimeters like 25mm × 47mm × 7mm. If the shaft has visible wear grooves, install a Durusleeve first before measuring for the replacement seal.
What is the difference between NBR, Viton, and Polyacrylate oil seals?
NBR (Buna-N) is the standard low-cost compound for mineral oils and hydraulic fluids up to 250°F. Viton (FKM) is the high-temperature, chemical-resistant compound rated to 400°F - required for fuels, synthetic oils, and aggressive chemicals. Polyacrylate (ACM) is the specialty compound for EP gear oils, ATF, and hot petroleum oils where NBR fails and Viton is overkill. Choose by operating temperature first, fluid compatibility second.
Are Durus oil seals interchangeable with CR, SKF, National, or Timken seals?
Yes - Durus follows industry-standard inch and metric sizing conventions. Any oil seal with matching inner diameter, outer diameter, width, case type, and lip configuration is functionally interchangeable. Texas Belting can cross-reference from any CR, SKF, National, Federal-Mogul, Chicago Rawhide, or Timken part number. Email sales@texasbelting.com with the existing part number or call (888) 203-2358.
How long do industrial oil seals typically last?
Service life depends on shaft speed, fluid temperature, lubrication, and contamination. Properly installed seals in clean operating conditions typically last 10,000 to 30,000 hours. Premature failure is usually caused by shaft wear grooves (use a Durusleeve to restore), misalignment causing eccentric runout, dry running, or incompatible fluid attack. Operating beyond the rated temperature range can degrade the elastomer within hours.
What is a Durusleeve and when do I need one?
A Durusleeve is a thin-wall stainless steel sleeve pressed onto a worn shaft to restore the sealing surface without machining or replacing the shaft. When an old oil seal lip has worn a visible groove in the shaft, installing a new seal on the same worn surface will cause immediate leakage. The Durusleeve provides a fresh, precision-ground OD for the new seal lip to ride on. Available for shafts up to 8" in diameter - see the Durusleeve collection.
Does Texas Belting stock the full Durus catalog?
Texas Belting stocks the full Durus catalog of 2,800+ inch and metric oil seals, Durusleeves, and end caps at our Houston, TX warehouse. In-stock items ship same day on orders placed before 3 PM CT. Specialty sizes, large-diameter seals over 12", and non-standard materials are typically available with 3-7 business day lead time. Call (888) 203-2358 to confirm stock status.
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.
For help choosing, see our oil seal size chart.
