Product Description

Mobiltac 375 NC, 325 NC and 275 NC extra high performance non-leaded, diluent-type, heavy-bodied open gear lubricants designed for a wide variety of open gear and mining applications. They contain a non-chlorinated, volatile solvent that ensures fluidity during application, even at low temperatures. Once applied, the diluent evaporates and the lubricants take on a flexible, adhesive, high-strength consistency that is maintained throughout their service life. Mobiltac 375 NC, 325 NC and 275NC adhere strongly to gear teeth and other machine elements to resist excessive throw-off, thereby providing a wear-resistant, viscous, continuous film that lubricates well under boundary conditions. Mobiltac 275 NC also contains solid phase EP/anti-wear additive for added equipment protection

Mobiltac 375 NC, 325 NC and Mobiltac 275NC will not harden, chip, or flake in cold weather, are self-healing, and do not form a hard-packed buildup in gear-tooth roots. Dripping and throw-off are minimal, and the lubricants are easily cleaned up with a solvent-soaked rag. The lubricants provide resistance to rain, snow, and process water washing. Their flash points minimise the risk of fire. These new generation gear and mining lubricants are applied easily by hand or by automatic dispensers. Mobiltac NC technology has rapidly become a firm favourite among many open gear users and mine operators around the world

Features and Benefits

The Mobiltac NC Series of products are the most recent technology advance for the Mobiltac brand of products that have been used with great success in open gear and other mining applications for several decades. These new technology products provide significantly improved environmental and performance benefits over older diluent-type technologies. They offer the following features and potential benefits:


Advantages and Potential Benefits

Excellent protection of gear teeth and other machine elements under boundary lubrication conditions

Less equipment wear and breakdown; lower replacement, downtime and maintenance costs

Excellent low-temperature pumpability

Easy start-up at low ambient and avoids cost of preheating

Excellent resistance to water washing

Maintains superb protection in wet environments; less unanticipated downtime

Minimal throw-off and dripping

Less product waste and new product cost

No chipping or flaking at low temperatures

Maintains protective lubricating film at low temperatures

Easy to clean up with rags and conventional solvents or cleaning fluids

Improved safety and reduced maintenance costs


Mobiltac 375 NC, 325 NC and Mobiltac 275NC are designed for use in a wide variety of open gear and mining applications:

• Mobiltac 375 NC, containing a high-viscosity base oil, is recommended for the lubrication of highly loaded open gears, including those that operate at high temperature, for example, ring gears on cement kilns and large gears on ore-processing mills

• Mobiltac 325 NC is recommended for the same applications as Mobiltac 375 NC. It contains more diluent and has a lower viscosity for ease of application at cooler temperatures

• Mobiltac 275 NC is designed for service as a lubricant for mine and quarry shovels, draglines, and related equipment; also open gears, racks and pinions, swing gears, booms and sticks

• Minimum operating temperature for Mobiltac 325 NC is -18 C, 375 NC is -1 C and 275 NC is -9 C

Properties and Specifications





Appearance, AMS 1738

Viscous, semi-fluid, black

Appearance, Visual

Viscous, semi-fluid, black

Viscous, semi-fluid, black

Density @ 15.6 C, kg/l, ASTM D1298



Flash Point, °C, ASTM D92


Flash Point COC With Solvent, F, ASTM D92


Flash Point, Cleveland Open Cup, °C, ASTM D92


Kinematic Viscosity 40 C (Diluted), cSt, ASTM D445


Kinematic Viscosity @ 100 C (Undiluted), cSt, ASTM D445



Specific Gravity, PTM 117


Health and Safety

Health and Safety recommendations for this product can be found on the Material Safety Data Sheet (MSDS) @


It cannot be guaranteed that the product information given above is up to date. For the latest version of the Product Data Sheet we refer to the product library of ExxonMobil.