To select the correct TBT OIL SEAL, I start with three basic dimensions: shaft diameter, housing bore diameter, and seal width. These dimensions are normally written as shaft diameter × housing bore diameter × width, such as 35 × 52 × 7 mm. I then verify the sealing material, shaft speed, temperature, fluid, pressure, and installation environment before confirming the final part number.
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This guide explains how I read TBT OIL SEAL size information, how I match a seal to an application, and what purchasing teams should confirm with a supplier. The dimensional examples below are for selection guidance and should not be treated as a complete TBT catalog. For production orders, I recommend sending the measured dimensions and operating conditions to TEBIETE for final confirmation.
As a practical example, a seal identified as 35 × 52 × 7 mm is intended for a nominal 35 mm shaft, a 52 mm housing bore, and a 7 mm axial installation width. A dimensionally correct seal can still fail if the elastomer is incompatible with the oil, the shaft surface is damaged, or the housing fit is unsuitable. For this reason, I treat size as the starting point, not the complete selection decision.
I prepared this guide for procurement specialists, maintenance teams, mechanical engineers, distributors, and OEM buyers who need to source rotary shaft seals. It is useful when replacing an existing seal, creating a new equipment specification, or comparing standard and customized sealing solutions. It can also help buyers organize the technical information required for a faster quotation.
The guide is particularly relevant to applications such as gearboxes, electric motors, pumps, agricultural machinery, hydraulic equipment, automotive assemblies, and general industrial rotating equipment. Each application can impose different requirements, so I recommend evaluating the complete operating environment instead of relying only on an old part number.
Most rotary oil seal dimensions are presented in the following order: shaft diameter × housing diameter × seal width. The shaft diameter describes the sealing lip’s nominal contact area, while the housing diameter describes the outside diameter that fits into the bore. The width indicates how much axial space the seal occupies after installation.
| Dimension | What It Describes | What I Check |
|---|---|---|
| Inside diameter | Nominal shaft size | Shaft measurement, wear, runout, and surface condition |
| Outside diameter | Nominal housing bore size | Bore measurement, roundness, damage, and retention method |
| Width | Axial installation space | Available cavity depth and neighboring components |
For accurate replacement, I measure the shaft and bore at several positions rather than relying on a single reading. This helps identify wear, ovality, or an assembly condition that may have caused the original seal to leak. If the measured dimensions differ significantly from the equipment drawing or previous seal, I ask for a technical review before ordering.
The following examples show how a buyer may organize size information. They are illustrative formats, not a statement that every size is available in every TBT profile or material.
| Example designation | Typical interpretation | Buyer verification point |
|---|---|---|
| 25 × 40 × 7 mm | 25 mm shaft, 40 mm bore, 7 mm width | Confirm cavity depth and shaft finish |
| 35 × 52 × 7 mm | 35 mm shaft, 52 mm bore, 7 mm width | Confirm rotation speed and oil type |
| 50 × 72 × 10 mm | 50 mm shaft, 72 mm bore, 10 mm width | Confirm housing retention and pressure exposure |
Common oil seal elastomers include NBR, FKM, silicone rubber, and selected specialty compounds. NBR is widely considered for general mineral-oil applications because it offers a practical balance of sealing performance and cost. FKM may be considered when higher temperature resistance or improved compatibility with certain fluids is needed, but the correct compound must still be matched to the specific oil and operating conditions.
The profile also affects performance. A standard single-lip design may be suitable where the main requirement is oil retention, while a secondary dust lip can add protection in dusty or dirty environments. Metal-cased, rubber-covered, and reinforced designs may be selected according to housing condition, installation method, corrosion exposure, and retention requirements.
I do not select a material from temperature alone. Fluid composition, additives, pressure, speed, intermittent operation, and cleaning chemicals can all influence service suitability. When the application is unusual, I provide the supplier with the fluid name, approximate temperature range, speed, and operating cycle so the proposed compound can be reviewed rather than assumed.
Temperature is one of the first operating factors I record. For example, an application operating near 80°C may have different material considerations from one operating near 120°C. These figures are selection checkpoints, not universal limits; the allowable range depends on the compound, fluid, lip design, speed, and actual heat transfer conditions.
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Rotational speed also matters because lip friction can generate heat. A shaft running at 1,500 rpm should not automatically use the same design selected for a slow gearbox, especially if lubrication is poor or the shaft surface is rough. I also check whether the seal is exposed to internal pressure, since many standard rotary seals are intended primarily for low-pressure oil retention rather than sustained high pressure.
Dust, water spray, mud, abrasive particles, and washdown chemicals can influence the preferred lip arrangement. For agricultural or outdoor machinery, I may consider a dust lip or additional external protection, while a clean electric motor may need a simpler configuration. The installation tool, insertion force, housing chamfer, and seal orientation should also be reviewed to prevent lip damage during assembly.
The shaft surface is equally important. Burrs, grooves, corrosion, excessive runout, and sharp edges can damage the sealing lip or create a leakage path. If a worn shaft cannot be repaired, I discuss alternatives such as a different installation position, a sleeve, or a modified seal arrangement with the engineering team and supplier.
This process reduces the risk of treating a nominally similar seal as an interchangeable part. I also keep the original seal marking, equipment model, and failure description in the purchasing record. That information is valuable when a repeat order is needed or when the original part has been discontinued.
A particularly common problem is confusing the seal’s nominal dimensions with the actual measured condition of the equipment. A worn shaft or damaged bore may require corrective work before a new seal can perform reliably. I therefore separate two questions: “What size seal was specified?” and “What condition is the assembly in today?”
Pricing for TBT OIL SEAL products can vary with size, material, profile, tooling, packaging, order quantity, and inspection requirements. Standard dimensions are often easier to quote than non-standard designs, while custom profiles may require drawing review or tooling discussion. I ask suppliers to state the material, dimensions, tolerance information, packaging method, and quotation validity clearly.
Minimum order quantity and lead time should be confirmed for each specific item rather than assumed from another size. I also check whether samples are available, whether repeat-order records can be maintained, and whether the supplier can support mixed sizes or scheduled purchasing. These details affect total sourcing risk even when the unit price appears attractive.
At TEBIETE, I support buyers by organizing the technical information needed to evaluate TBT OIL SEAL requirements. This may include dimensional review, material discussion, profile confirmation, sample coordination, packaging requirements, and export order communication. Where the application data is incomplete, I prefer to identify the missing information instead of making an unsupported specification claim.
For an inquiry, I recommend sending the required size, quantity, equipment application, fluid, temperature, speed, pressure, environmental conditions, drawing or photo, and expected delivery schedule. If you have an existing seal, its marking and clear images can also help narrow the selection. TEBIETE can then review whether a standard solution or a customized option is more appropriate.
The correct TBT OIL SEAL selection requires more than matching one number. I first confirm the three dimensions—shaft diameter, housing bore, and width—then evaluate material, lip profile, fluid, temperature, speed, pressure, contamination, and installation conditions. This approach gives procurement and engineering teams a clearer basis for comparing suitable options.
As the next step, measure the assembly, document the operating conditions, and prepare any available drawings or old-seal photos. Send that information to TEBIETE for a focused quotation and technical review. With complete input data, I can help you assess the appropriate TBT OIL SEAL size, material, profile, packaging, and supply plan before you place a production order.
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