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Genuine Lubrication

Experience shows the cause of 90% of hydraulic component failure is hydraulic oil related (contamination, old oil etc).

Using advanced refining technology that produces a premium hydro-cracked base oil with a zinc free formulation (for superior sludge control), Hitachi hydraulic oil is developed specifically for Hitachi equipment. HN46 Hitachi hydraulic oil ensures your equipment continues to function at peak levels, protects hydraulic components from wear and lowers your cost of ownership because of extended change out interval of 4,000 hours*

*If not mixed with other brands.

More than just oil, Hitachi 46HN is the lifeblood of your equipment’s hydraulic circuit.


The combination of high temperatures, high pressure, air and the hydrocarbons in your hydraulic oil can lead to a reactive mixture.

Oxidation raises an oils' viscosity causing an increase in friction. Greater friction increases the rate of oxidation and this cycle causes your hydraulic oil to break down.

The chart below illustrates the level of oxidation using a Millipore filter test performed on an oil sample taken from an Indiana stirring oxidation test (ISOT) measuring the stability of oil.


Result Chart of Oxidation Test

Test: Millipore filter test performed on oil sample taken from Indiana Stirring Oxidation Test (ISOT). ISOT: 165.5C, 1,300rpm, with Fe/Cu catalyst. Millipore filter: mg contaminant/100ml solvent from a 0.8 micron filter.

Circulating Pump Test

The circulating pump test evaluates the level of oxidation in hydraulic oil.
In this test, 3 leading hydraulic oil brands including Hitachi 46HN were visually inspected at the start, then at 200 and 500 hour intervals.

From the results below it is clear that the Hitachi sample shows much less colour change indicating less oxidation.

Oil at Start

Oil after 200 Test Hours

Oil after 500 Test Hours

Test: Circulating pump test, 80C, pump pressure: 350 kg/cm2


Hitachi 46HN Benefits:

  • Pure hydro cracked base oil resists oxidation
  • Reduced operating temperatures
  • Extended lubricant service life
  • Reduced varnish and carbon deposits
  • Improved fuel efficiency

Zinc Free Formulation Provides Superior Sludge Control

The accumulation of viscous deposits can plug valves and filters, reduce actuator response, increase pump abrasion and shorten oil’s useful service life.
Zinc is widely used in hydraulic oil as part of a compound that reduces metal wear. During operation, zinc can separate from this compound and combine with other elements in the oil with results in a viscous, sludge like product that is difficult to remove.
Because Hitachi 46HN Hydraulic oil is zinc free, sludge generation is significantly reduced as illustrated in the 2 scenarios below.

Zinc Free Formulation Provides Superior Sludge Control

Zinc-Free Hitachi 46HN Hydraulic Oil

Hydro-cracked Zinc Hydraulic Oil

Hitachi 46HN Benefits:

  • Reduced sludge generation
  • Improved filter and component life
  • Reduced varnish
  • Better fuel efficiency

Reduction of metal wear

One primary function of hydraulic oil is to coat metal surfaces with a protective film – eliminating metal-to-metal contact and reducing wear.
The Shell 4 ball wear test assesses the capability of lubricating oils to prevent wear in highly loaded environments.
In this test, 1 fixed ball is rotated around 3 fixed balls at 1200rpm and weighted to 30kg for 30 minutes. The wear is then measured.
From the charting below, Hitachi 46HN hydraulic oil recoded the lowest wear of all samples.

Result Chart of Metal Wear TestShell 4 Ball Wear Test, 1200 rpm. 30KG, 30min, wear measured in mm

In addition, levels of acid generation (which is an indication of gum and lacquer build up on components) was tested across the samples. Hitachi 46HN recorded the lowest levels, indicating low amounts of acidic components within the oil.

Result Chart of Acidity TestTAN on Samples after ISOT, 165.5C, 48hrs


Hitachi 46HN Benefits:

  • Extended equipment life by reducing metal wear
  • Molecularly binds exposed metal surfaces, preventing metal-to-metal contact
  • Prevents the generation of acids that can corrode equipment

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