The UNIVERSAL Oil Seal 3.938x5.250x0.500 LGS NBR is designed for industrial rotary shaft applications requiring lubricant retention around a 3.938-inch shaft.

Installed between the rotating shaft and stationary housing, the sealing element maintains controlled radial contact with the shaft surface. This helps reduce leakage of compatible oil or grease while protecting bearings, gears, pumps, transmissions, and other internal rotating components from dust, moisture, and contaminants.

The product is identified by the UNIVERSAL manufacturer designation LGS. This is a manufacturer-specific profile code. The exact sealing-lip geometry, number of lips, dust-exclusion arrangement, outside-case construction, internal reinforcement, spring configuration, lip orientation, and installation direction should be verified against the original seal, technical drawing, or equipment specification before replacement.

Manufactured from NBR (Nitrile Butadiene Rubber), the sealing element is generally suitable for:

• Mineral oils
• Gear oils
• Hydraulic oils
• Bearing grease
• Petroleum-based lubricants
• General industrial lubricating fluids

NBR provides good resistance to petroleum-based oils, grease, abrasion, and mechanical wear under normal industrial operating conditions. Compatibility should be verified before use with aggressive chemicals, fuels, continuous high temperatures, ozone-rich environments, or specialized synthetic lubricants.

The inch dimensions convert approximately to:

Shaft diameter: 3.938 inches or approximately 100.03 mm

Housing diameter: 5.250 inches or 133.35 mm

Seal width: 0.500 inch or 12.70 mm

The 3.938 × 5.250 × 0.500-inch configuration is suitable for medium-to-large bearing housings, heavy industrial gearboxes, pumps, transmissions, conveyor drives, and legacy machinery using a large inch-size shaft-sealing arrangement.

For a seal of this size, shaft finish, shaft hardness, housing alignment, concentricity, shaft runout, installation depth, and even lip lubrication are particularly important for reliable service life.

⚙️ Applications

• Heavy industrial gearboxes
• Large bearing housings
• Industrial pumps
• Mechanical transmissions
• Power transmission systems
• Agricultural machinery
• Construction equipment
• Conveyor drive assemblies
• Legacy industrial equipment
• OEM rotating machinery

🎯 Benefits

✔ Helps retain compatible oil or grease

✔ Protects bearings and internal components

✔ Oil-resistant NBR sealing material

✔ Suitable for approximately 100 mm shaft assemblies

✔ Manufacturer-specific UNIVERSAL LGS profile

✔ Good resistance to abrasion and wear

✔ Robust 0.500-inch axial width

✔ Suitable for maintenance and overhaul work

✔ Replacement ready when dimensions and profile match

🧠 Technical Insight

• UNIVERSAL LGS Seal Reference
• Large Inch-Size Rotary Shaft Seal
• NBR Sealing Material
• Manufacturer-Specific LGS Profile
• Low-Pressure Lubricant Retention
• Shaft Alignment and Runout Are Critical
• Approximately 100.03 mm Shaft Diameter
• Exact LGS Cross-Section Must Be Verified

✅ Key Features

• UNIVERSAL Industrial Seal
• LGS Profile Reference
• Oil-Resistant NBR Material
• Large Inch-Size Construction
• 3.938x5.250x0.500 Dimensions
• Suitable for Compatible Oil and Grease
• Heavy Industrial Replacement Seal
• Cross-Reference Support Available

📊 Specifications

Brand: UNIVERSAL

Model / Profile: LGS

Size: 3.938 × 5.250 × 0.500 inch

Metric Equivalent: Approximately 100.03 × 133.35 × 12.70 mm

Type: Large Industrial Rotary Shaft Oil Seal

Material: NBR (Nitrile Butadiene Rubber)

Profile: LGS

Construction: Manufacturer-Specific UNIVERSAL LGS Rotary Shaft-Seal Construction

Lip Design: LGS profile; verify the exact sealing-lip geometry, number of lips, and orientation against the original seal or technical drawing

Dust Lip: Verify from the actual LGS cross-section

Spring Type: Verify from the actual seal construction

Shaft Diameter (ID): 3.938 inches / approximately 100.03 mm

Housing Diameter (OD): 5.250 inches / 133.35 mm

Width: 0.500 inch / 12.70 mm

Pressure Capability: Low-pressure rotary shaft-sealing service unless otherwise specified

Lubrication: Compatible oil and grease

Temperature Range: Typically approximately -30°C to +100°C for standard NBR; verify the actual compound, lubricant, shaft speed, and operating conditions

Speed Consideration: Permissible speed depends on shaft diameter, surface finish, lubrication, temperature, alignment, runout, and NBR compound

Installation Consideration: Confirm shaft finish, concentricity, housing-bore condition, installation depth, and lip direction before fitting

Application Class: Medium-to-Large Industrial Bearing and Rotating Equipment

Standard: Inch-Size Specialized Industrial Seal

🔁 Equivalent

Suitable replacement or cross-reference candidate for compatible:

• UNIVERSAL LGS NBR Rotary Shaft Seal
• UNIVERSAL 3.938x5.250x0.500 Oil Seal
• 100.03x133.35x12.70 Rotary Seal
• Approximately 100 mm Shaft Oil Seal
• Large Inch-Size NBR Rotary Shaft Seal
• Industrial Bearing Housing Seal
• Heavy Gearbox Shaft Seal
• Industrial Pump Shaft Seal
• OEM LGS Profile Oil Seal
• Large Industrial NBR Shaft Seal

The same dimensions alone do not guarantee interchangeability. The replacement must match the original LGS cross-section, sealing-lip geometry, lip orientation, outside-case construction, reinforcement arrangement, spring configuration, installation direction, material compound, and operating requirements.

(Always verify dimensions, LGS-profile geometry, lip direction, shaft finish, shaft hardness, housing condition, installation depth, lubricant compatibility, rotational speed, temperature, alignment, concentricity, runout, pressure, and operating conditions before ordering.)

📦 Availability

✅ In Stock

🚚 Fast Delivery Available

🌎 Worldwide Shipping Available

📦 MOQ: 1 Piece

🏭 Suitable for heavy gearbox overhaul, large bearing-housing maintenance, industrial pump repair, transmission servicing, agricultural-machinery repair, construction-equipment maintenance, conveyor-drive servicing, legacy-equipment restoration, and compatible OEM replacement applications.

📲 Contact via LINE ID: dusitrea

📧 Email: sales@seal4go.com

💬 Technical support available before ordering

🔍 Assistance available for cross-reference and equivalent part identification