One of the most important oils in the automotive, heavy, aviation and aerospace
industries is hydraulic oil. The main task of hydraulic oil is power
transmission and lubrication in the relevant part. If you’ve ever felt the pressure of choosing the right hydraulic oil for
your machinery, you’ll know all too well the minefield of information
that’s out there in books or online. Instead of getting lost in the
world of hydraulic fluid, hydraulic liquids or hydraulic lubricants, why
not take a look at our easy to follow guide to hydraulic oil? It’s everything you need to know about hydraulic oils!
This type of oil makes the
hydraulic parts move better and transfers power to other parts easily.
of hydraulic oil in the car is to act as a fluid to move the parts and speed up
types of hydraulic oil :
1- Type of petroleum
oil: from crude oil refining & mineral bases , but is quality is good,price is low & good ,are in all markets.
2-A type of synthetic oil that uses pressure and current factors to
transfer power. Hydraulic oil has vital applications in passenger aircraft such
as moving wing surfaces and landing gear, and in heavy industry pumps, jacks
Oil performance depends on the correct viscosity of the oil, system
type, operating temperature, acidity, R&O, absorption rate.
the resistance of the oil layer.
Hydraulic oil standards are subject to the
International Organization for Standardization (ISO) and some standards of
important factories such as SIEMENS, ALESTOM, etc.
Hydraulic oil classification
classifications of hydraulic oil are a subgroup of different fluids
with varying performance levels. Below is a list of common hydraulic oil
classifications and their respective descriptions:
- HL – Refined mineral oils with anti-oxidation & anti-rust properties: Mineral hydraulic oil with good lifting ability & longer storage time in the system
- HM – HL with improved anti-wear properties :Mineral hydraulic oil with good ability to prevent wear, improved by anti-wear additive and...
- HR – HL oils with VI improvers:Mineral hydraulic oil with high capability and high improved viscosity index for car and elevator systems and...
For a detailed list, you can speak with our knowledgeable team by contact us alternatively, you can read our mail explainer of esyekta website .
What is hydraulic oil?
Hydraulic oil is a non-compressible fluid that is used to transfer power within hydraulic machinery and equipment. Otherwise known as hydraulic fluid, hydraulic oil can be synthetic- or mineral-based.
At yekta co, as a hydraulic oil supplier, we deal with 99% of mineral-based hydraulic oils.
Although this useful fluid is commonly used in the transfer of power, hydraulic fluid can act as a sealant, coolant and lubricant within machinery and equipment.
The main difference between synthetic and mineral based hydraulic oil
The majority of oils which are produced are either mineral based or synthetic. Mineral based hydraulic oils are derived from crude oil fractions whereas synthetic hydraulic oils are made using chemically produced base fluids.
Synthetic oils can be formulated to impart superior physical properties in comparison to mineral oils, for example high temperature performance, biodegradability and oxidation stability.
What is hydraulic oil used for?
fluids are used in many applications across every industry. To give you
an idea of the vast array of uses for hydraulic fluid and why
industrial hydraulic oil is so important, here are 10 examples of equipment and machinery which use hydraulic oil:
- Forklift Trucks
– The hydraulic system within forklift trucks and stackers is important
to help power the incredibly strong forks which need to lift some
- Log Splitters – The ram
mechanism on a hydraulic oil log splitter requires hydraulic fluid
inside to give it that immense power which can split logs with ease. Log
splitters are also known as wood splitters!
- Automotive Lifts
– Car lifts (car jacks, automotive lifts, etc.) require hydraulic jack
oil to aid their impressive power range! This type of machinery depends
heavily on reliable hydraulic oil for safety as well as performance.
Hydraulic fluid for a car lift tends to have a higher viscosity grade
for high pressure.
- Wright Standers – A wright
stander is a stand on mower which is usually well-suited to cemeteries
and other restrictive grassy areas. The hydraulic part of these machines
requires hydraulic oil for power.
- Snow Ploughs (Snow Plows)
– Hydraulic oil for a snow plough and ploughing equipment is essential
in the powerful operation of the hydraulic lift, tilt and angle
movements of the snow plough blade. The cold weather conditions
associated with the use of a plough means that the hydraulic fluid used
in a snow plough will be blended with antifreeze additives.
- Skid Steers (Skid-steer Loader and Skidsteer)
– Skid steer hydraulic oil is as versatile as the machine it works
with. For the many tasks this machine can competently complete,
hydraulic oil plays a big role at all times.
- Aircraft (aviation)
– In the aviation sector, it is essential that aircraft hydraulic oil
is reliable as it is used for aviation control systems, aircraft hangar
doors, aircraft jacks and aircraft controls.
- Air Tools – Air tools and air compressors require high-pressure hydraulic oil which contains anti-wear additives for protection.
- Tractors –
Tractor hydraulic oil is necessary for the operation of hydraulic
brakes and hydraulic systems on agricultural vehicles and machinery. For
your hydraulic oil tractor supply, you may want to use a reputable
manufacturer to ensure your expensive machinery and vehicles are well
looked after and protected.
- Cruise Ships and the Marine Industry
– If you’ve been lucky enough to go on a cruise ship then you’ll have
felt the comforts out at sea. Hydraulic oil is used aboard many marine
vessels for the stabilisers. The stabilisers reduce the amount of roll,
which can affect the ship’s balance and cause you to experience
unfriendly sea-motion sickness. This is just one of the many other
applications on marine vessels which require hydraulic oil.
please follow :
When it comes to hydraulic oils, viscosity is the measurement of its resistance to flow and it is an important property of hydraulic fluids. This means the fluid will resist compression at different rates depending on its viscosity and take longer to pass through an orifice as the viscosity increases.
Hydraulic fluid with high viscosity will be thicker and harder to compress and move as opposed to low viscosity hydraulic oil which will be thinner and pass through easier.
The viscosity of a hydraulic fluid is measured in Centistokes (cSt) and usually at temperatures of 40°C & 100°C. The value will always have the temperature next to it as without this the value will be meaningless. A fluid’s viscosity is measured in a petroleum laboratory using a viscometer !
Viscosity Index Improvers
were first used to make multi-grade engine oils in the 1940s. These
days, this common and well-tested technology is used to make high VI
oils for other applications, including automotive transmission fluids
and manual transmission gear oils. However, the VI improvers used in
oils for the aforementioned applications are not typically shear stable
when used in modern hydraulic systems.
But, recent advances in VI improver technology mean that mineral
hydraulic oils with a shear-stable viscosity index in the 150 to 200
range are now commercially available.
While this may be good to know, what does it really mean to a hydraulic
equipment owner? Well, within the allowable extremes of viscosity
required to maintain adequate lubricating film thickness for hydraulic
components, there’s a narrower viscosity range where power losses are
minimized and, therefore, power transfer is maximized.
By maintaining the oil’s viscosity in this optimum range, machine cycle
times are faster (productivity is increased) and power consumption
(diesel or electricity) is reduced.
So, using a higher VI oil means the hydraulic system will remain in its
power transmission “sweet spot” across a wider operating temperature
range. You could think of this as similar to installing an automatic
tensioner on the V-belt drive we talked about earlier in order to
maintain optimum power transfer conditions.
Hydraulic oil viscosity is important for each different application.
Hydraulic oil is different than other lubes. Not only is it a
lubricant, it’s also the means by which power is transferred throughout
the hydraulic system. So, it’s a lube and a power transfer device. This
dual role makes it unique.
To be an effective and reliable lubricant, hydraulic oil must possess
properties similar to most other lubes. These include: foaming
resistance and air release; thermal, oxidation and hydraulytic stability ;
anti-wear performance; filterability ; demulsibility; rust and corrosion
inhibition; and viscosity in respect of its influence on film
To be most efficient in its role as a power transfer device, hydraulic
oil needs high bulk modulus (high resistance to reduction in volume
under pressure) and high viscosity index (low rate of change in
viscosity with temperature).
As an analogy, consider the tension on a V-belt. If it is out of
adjustment, the belt will slip. The result is a higher percentage of
input power wasted to heat. This means less power is available at the
output to do useful work. In other words, the drive becomes less
A similar situation can occur with hydraulic oil. Change in its bulk
modulus and/or viscosity can affect the efficiency with which power is
transferred in the hydraulic system.
The wrong viscosity could cause damage to equipment or have poor results in function.