The HUMPHREY Oil Seal 3.250x4.125x0.438 M/L Leather is designed for industrial rotary shaft applications requiring lubricant retention around a 3.250-inch shaft.

Installed between the rotating shaft and stationary housing, the leather sealing element maintains controlled radial contact with the shaft surface. Oil-treated industrial leather can adapt to minor shaft-surface irregularities and is particularly suitable for machinery originally designed around traditional leather shaft seals.

The product is identified by the HUMPHREY manufacturer designation M/L. This is a manufacturer-specific profile code. The exact leather-lip geometry, metal-support arrangement, outside-case construction, lip orientation, installation direction, and internal retaining features should be checked against the original seal or technical drawing before replacement.

Industrial leather shaft seals are commonly used with:

• Mineral oils
• Gear oils
• Bearing grease
• Petroleum-based lubricants
• Slow-to-moderate shaft speeds
• Older or specialized industrial machinery

Leather sealing elements can perform well on slightly worn shaft surfaces when adequately lubricated. However, performance depends strongly on the leather grade, oil treatment, shaft finish, lubrication, temperature, rotational speed, housing alignment, and installation method.

Leather seals should not normally operate dry. Compatibility should also be verified before use with water-rich environments, aggressive chemicals, specialized synthetic lubricants, or elevated temperatures.

The inch dimensions correspond approximately to:

Shaft diameter: 3.250 inches or 82.55 mm

Housing diameter: 4.125 inches or 104.78 mm

Seal width: 0.438 inch or approximately 11.13 mm

The 3.250 × 4.125 × 0.438-inch dimensions make this seal suitable for medium-to-large bearing housings, industrial gearboxes, transmissions, pumps, agricultural machinery, and legacy OEM equipment using an inch-size leather sealing arrangement.

⚙️ Applications

• Industrial gearboxes
• Bearing housings
• Mechanical transmissions
• Agricultural machinery
• Construction equipment
• Conveyor drive assemblies
• Industrial pumps
• Legacy machine tools
• Vintage industrial equipment
• OEM rotating machinery

🎯 Benefits

✔ Helps retain compatible oil or grease

✔ Genuine industrial leather sealing element

✔ Can adapt to minor shaft-surface irregularities

✔ Suitable for 3.250-inch shaft assemblies

✔ Metal-supported industrial construction

✔ Suitable for legacy machinery restoration

✔ Appropriate for maintenance and overhaul work

✔ Supports equipment originally designed for leather seals

✔ OEM replacement ready when dimensions and profile match

🧠 Technical Insight

• HUMPHREY M/L Seal Reference
• Inch-Size Rotary Shaft Seal
• Oil-Treated Industrial Leather
• Metal-Supported Seal Construction
• Low-Pressure Lubricant Retention
• Adequate Lubrication Required
• 82.55 mm Shaft Diameter
• M/L Cross-Section Verification Required

✅ Key Features

• HUMPHREY Industrial Quality
• M/L Profile Reference
• Genuine Leather Sealing Material
• Metal Case and Support Structure
• Inch-Size 3.250x4.125x0.438 Dimensions
• Suitable for Compatible Oil and Grease
• Legacy Industrial Replacement Seal
• OEM Cross-Reference Ready

📊 Specifications

Brand: HUMPHREY

Model: M/L

Size: 3.250 × 4.125 × 0.438 inch

Metric Equivalent: Approximately 82.55 × 104.78 × 11.13 mm

Type: Industrial Leather Rotary Shaft Seal

Material: Oil-Treated Genuine Industrial Leather with Metal Case and Support

Profile: M/L

Construction: Manufacturer-Specific Metal-Supported Leather Shaft-Seal Construction

Lip Design: M/L leather profile; verify the exact lip geometry and orientation against the original seal

Dust Lip: Normally not included unless the original construction specifically indicates otherwise

Spring Type: No spring unless the original seal construction specifically indicates otherwise

Shaft Diameter (ID): 3.250 inches / 82.55 mm

Housing Diameter (OD): 4.125 inches / 104.78 mm

Width: 0.438 inch / approximately 11.13 mm

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

Lubrication: Compatible oil or grease; adequate lubrication is required

Temperature Range: Depends on leather grade, lubricant, shaft speed, and operating conditions; verify against the original application

Speed Consideration: Generally suitable for slow-to-moderate shaft speeds, subject to lubrication, shaft finish, temperature, alignment, and seal construction

Application Class: Legacy and Specialized Industrial Rotating Equipment

Standard: Inch-Size Specialized Leather Seal

🔁 Equivalent

Suitable replacement for compatible:

• HUMPHREY M/L Leather Shaft Seal
• HUMPHREY 3.250x4.125x0.438 Seal
• 82.55x104.78x11.13 Leather Seal
• 3.250-Inch Shaft Leather Seal
• Metal-Supported Leather Oil Seal
• Industrial Bearing Housing Leather Seal
• Gearbox Leather Shaft Seal
• Legacy Machinery Oil Seal
• OEM M/L Leather Seal
• Industrial Leather Rotary Seal

The same dimensions alone do not guarantee interchangeability. The replacement must match the original M/L cross-section, leather-lip geometry, lip orientation, metal-support arrangement, outside-case construction, installation direction, leather grade, and lubrication requirements.

(Always verify dimensions, M/L-profile geometry, lip direction, shaft finish, housing condition, installation depth, lubricant compatibility, rotational speed, temperature, and operating conditions before ordering.)

📦 Availability

✅ In Stock

🚚 Fast Delivery Available

🌎 Worldwide Shipping Available

📦 MOQ: 1 Piece

🏭 Suitable for gearbox overhaul, bearing-housing maintenance, agricultural-machinery repair, construction-equipment maintenance, conveyor-drive servicing, industrial pump repair, 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