The NATIONAL 3.125x4.003x0.468 M/R NBR Oil Seal is designed for industrial applications where dependable sealing performance, lubricant retention, and protection against contamination are critical to equipment reliability and operational efficiency.

The M/R Profile combines a reinforced metal outer case with a precision-engineered sealing lip and garter spring assembly. This design provides excellent dimensional stability while maintaining consistent sealing pressure against the shaft under continuous operation, vibration, and varying load conditions.

The spring-loaded sealing lip effectively prevents oil leakage while protecting bearings, shafts, and internal machine components from dust, dirt, moisture, and external contaminants. This helps reduce wear, extend equipment service life, and minimize maintenance requirements.

Manufactured from premium NBR (Nitrile Butadiene Rubber), the sealing element offers excellent resistance to lubricating oils, hydraulic fluids, gear oils, grease, and petroleum-based lubricants. NBR is widely recognized as the industry's most commonly used sealing material due to its excellent balance of oil resistance, flexibility, durability, and cost-effectiveness.

With dimensions of 3.125 x 4.003 x 0.468 inch, this oil seal is commonly found in industrial pumps, gearboxes, agricultural equipment, compressors, conveyors, speed reducers, and imported machinery utilizing inch-size shaft systems.

NATIONAL oil seals are widely trusted for industrial maintenance, machinery rebuilding, OEM replacement, and heavy-duty rotating equipment applications.

⚙️ Applications

• Industrial gearboxes
• Industrial pumps
• Hydraulic equipment
• Agricultural machinery
• Air compressors
• Conveyor systems
• Speed reducers
• Construction equipment
• Power transmission systems
• OEM industrial machinery

🎯 Benefits

✔ Excellent oil retention

✔ Superior contamination protection

✔ Extend bearing and shaft life

✔ Reduce lubricant leakage

✔ Lower maintenance costs

✔ Reduce machine downtime

✔ Improve equipment reliability

✔ Suitable for continuous-duty operation

✔ Heavy-duty industrial performance

🧠 Technical Insight

• M/R heavy-duty industrial profile
• Reinforced metal case construction
• Spring-loaded sealing lip maintains constant pressure
• Excellent dimensional stability under vibration and load
• NBR provides excellent oil and wear resistance
• Suitable for oil and grease lubrication systems
• Designed for harsh industrial environments
• Commonly used in pumps, gearboxes, and transmission equipment

✅ Key Features

• NATIONAL Industrial Quality
• M/R Heavy Duty Design
• Reinforced Metal Case
• Spring Loaded Sealing Lip
• Premium NBR Material
• Excellent Wear Resistance
• OEM Replacement Ready
• Long Service Life

📊 Specifications

Brand: NATIONAL

Model: M/R

Size: 3.125 x 4.003 x 0.468 inch

Type: Heavy Duty Rotary Shaft Oil Seal

Material: NBR (Nitrile Rubber)

Construction: Reinforced Metal Case

Spring Type: Garter Spring

Shaft Diameter (ID): 3.125 inch

Housing Diameter (OD): 4.003 inch

Width: 0.468 inch

Lubrication: Oil & Grease

Application Class: Heavy Industrial Service

Standard: Inch Size Oil Seal

🔁 Equivalent

Suitable replacement for:

• SKF Industrial Oil Seal
• CR Chicago Rawhide Oil Seal
• Federal-Mogul Oil Seal
• NOK Industrial Oil Seal
• CFW Rotary Shaft Seal
• KACO Oil Seal
• DICHTOMATIK Oil Seal
• TRELLEBORG Rotary Seal

(Always verify dimensions and seal profile before ordering.)

📦 Availability

✅ In Stock

🚚 Fast Delivery Available

📦 MOQ: 1 Piece

📲 Contact via LINE ID: dusitrea

🏭 Suitable for industrial maintenance, machinery overhaul, OEM replacement, and repair workshop applications