Mobiltac 50M Series


The Mobiltac 50M Series of premium performance open gear lubricants is designed to provide outstanding protection of heavily loaded open gears exposed to severe operating conditions. Mobiltac 50M is a semi-synthetic open gear lubricant containing high performance additives designed to provide an adhesive film and excellent load carrying capability particularly for open gears on shovels, draglines, and associated mining equipment.


Product series information

Features and Benefits

Mobiltac 50M has the following features and potential benefits:

  • Very high viscosity, semi synthetic lubricant designed to extend component life in heavily loaded open gear applications 
  • Excellent wash-off resistance in very wet operating environments
  • Solid anti-wear and extreme pressure protection of mating surfaces against damaging wear in contact zones
  • Available in three grades for different ambient operating conditions. 
  • Mobiltac 50M Heavy is recommended for ambient temperatures >20°F (-7°C) Mobiltac 50M Light is recommended for ambient temperatures from -15°F (-26°C) to 70°F (21°C) while Mobiltac 50M Arctic is recommended for ambient temperatures <500F (10°C).
  • Weld load protection > 800 kg


Mobiltac 50M is recommended for the lubrication of:

  • Open gears on shovels, draglines and associated mining equipment with spray, brush or drip application
  • The hoist gear on Caterpillar Mining electric rope shovels and in applications where an extra heavy open gear lubricant is desired

Typical Properties

Mobiltac 50M Arctic Mobiltac 50M Light Mobiltac 50M Heavy
Color, Visual Black Black Black
Appearance, Visual Viscous Semi-Fluid
Viscous Semi-Fluid Viscous Semi-Fluid
Specific Gravity, ASTM D-1298 1.00 1.01 1.02
Flash Point, ASTM D-92 290oF (143oC)
284°F (140°C) 300°F (149°C)
4 Ball EP Weld Point (kg) (undilute), ASTM D-2596 >800
>800 >800
Rust, ASTM D-1743 Pass Pass Pass
Copper Strip Corrosion, ASTM D-4048 1A 1A 1A
Ventmeter, 600 psi, Lincoln VE-1 -30°F @ <30 sec
-15°F @ <150 sec 20°F @ <30 sec
Base Oil Viscosity at 40°C, ASTM D445 50,000 cSt
50,000 cSt 50,000 cSt
Optimal Ambient Operating Temperature Range -40°F (-40°C) to 50°F (10°C)
-15°F (-26°C) to 70°F (21°C) 20°F (-7°C) to 120°F (49°C)


Health and Safety

Based on available information, this product is not expected to produce adverse effects on health when used for the intended application and the recommendations provided in the Material Safety Data Sheet (MSDS) are followed. MSDS's are available upon request through your sales contract office, or via the Internet. This product should not be used for purposes other than its intended use. If disposing of used product, take care to protect the environment.