Castrol Optigear BM 680 - Gear oils with MFT - 3521

Castrol Optigear BM 680 - Gear oils with MFT - 3521

Castrol Optigear BM 680 - Gear oils with MFT - 3521


Castrol Optigear™ BM are solid-free high performance gear oils containing the additive combination Microflux Trans™ (MFT). Designed to reduce wear caused by surface fatigue, pitting, spalling, scuffing, scoring or irregularities during running-in period and during normal operations.

Microflux Trans (TRANS=Triple Action Non-sacrificial Surface engineering) improves friction surfaces to an extent not possible with normal machining processes and conventional Extreme Pressure (EP) lubricants. In a tribological system, the polarized MFT additives instantaneously create a passive film on friction surfaces before friction occurs. At a given load level, the MFT additives create a resistant protective layer on friction surfaces.
Under severe load, components of the MFT additive combination are activated and diffuse into the surfaces initiating an improvement of their friction characteristics through plastic deformation. The organic reaction products become a component of the tribopolymer system. Unlike the case with conventional lubricants, the tribopolymers formed by MFT are long-chained compounds with excellent lubricity and adhesion. The load carrying area is improved and the hydrodynamic lubrication film is easier to maintain. This unique physical-chemical reaction is
Castrol surface engineering and achieves a non-sacrificial micro-smoothing of the friction surfaces. The MFT additive technology provides optimum wear protection and an extremely low coefficient of friction even under extremes of pressure, vibration, shock loads, at high or low speeds or varying operational conditions.

Optigear BM gear oils are in conformity with and even exceed the requirements of DIN 51517 part 3 CLP and AGMA specifications 9005-D94 for EP Gear Oil.



  • In all types of industrial gears, especially operating under extremely heavy loads, where conventional EP oils fail.
  • Long term lubrication under the most extreme mechanical conditions, vibrations and elevated temperatures.
  • Spur and bevel gears, worm gears up to the medium load range.
  • Gears exposed to high sliding friction and high Hertzian surface pressures up to 2000 N/mm2 (elevators, rolling mills, belt conveyors, extruders, vibrating equipment, crushers, high speed looms and separators).
  • Eccentrics, cam shafts and planetary gears.
  • Variable speed drives (PIV).
  • Sealed gear couplings.
  • In all types of bearings, especially for spherical roller bearings, full complement cylindrical roller bearings and thrust bearings.
  • Circulation systems.



  • Extended lifetime of machine elements and wear parts, lower maintenance and labour costs by minimised wear and friction.
  • Full load operation within shortest time, virtually eliminating the running-in period.
  • Lower costs for lubricants and waste oil disposal because of significant extensions of both service life and re-lubrication intervals.
  • Energy savings due to reduced coefficient of friction, lower temperature of lubricant and component and improvement in operating efficiency.
  • Product consolidation i.e. simplification and reduction of lubricants and spare parts.
  • Reduction of noise resulting from high frequency stick-slip for ‘life’ lubrication in some applications.
  • Smoothing of existing pittings.


Additional Information:

  • Miscible and compatible with unleaded gear oils based on mineral oil. However, maximum performance is only guaranteed if not mixed with any other product.
  • Compatible with non-ferrous metals.
  • Compatible with paints and conventional sealing materials.
  • Mechanical cleaning with all known filtering installations and separators possible


Pack sizes available - 20L

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