{"id":99516,"date":"2019-05-08T15:30:35","date_gmt":"2019-05-08T14:30:35","guid":{"rendered":"https:\/\/www.crownoil.co.uk\/?page_id=99516"},"modified":"2025-07-15T14:05:23","modified_gmt":"2025-07-15T13:05:23","slug":"hydraulic-oil-guide","status":"publish","type":"page","link":"https:\/\/www.crownoil.co.uk\/guides\/hydraulic-oil-guide\/","title":{"rendered":"Guide to Hydraulic Oil"},"content":{"rendered":"\n
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What is Hydraulic Oil and What is it Used For?<\/h2>\n\n\n\n

If you\u2019ve ever felt the pressure of choosing the right hydraulic oil for your machinery, you\u2019ll know all too well the minefield of information that\u2019s 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<\/a>? It’s everything you need to know about hydraulic oils!<\/p>\n\n\n\n

Hydraulic oil is available for delivery nationwide, within 24-48 hours of purchase. Give our hydraulic experts a call today on 0330 123 1444<\/a>.<\/p>\n<\/div>\n\n\n\n

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Contents<\/h3>\n\n\n\n
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  1. What is hydraulic oil?<\/a><\/li>\n\n\n\n
  2. Main difference between synthetic and mineral-based hydraulic oil<\/a><\/li>\n\n\n\n
  3. How do hydraulic systems work<\/a><\/li>\n\n\n\n
  4. What is hydraulic oil used for?<\/a><\/li>\n\n\n\n
  5. Hydraulic fluid properties<\/a><\/li>\n\n\n\n
  6. Contents of hydraulic oil<\/a><\/li>\n\n\n\n
  7. Hydraulic oil additives<\/a><\/li>\n\n\n\n
  8. Hydraulic oil for winter<\/a><\/li>\n\n\n\n
  9. Hydraulic oil for high heat applications<\/a><\/li>\n\n\n\n
  10. Hydraulic oil for heavy duty use<\/a><\/li>\n\n\n\n
  11. Environmentally friendly hydraulic oil<\/a><\/li>\n\n\n\n
  12. Hydraulic oil classification<\/a><\/li>\n\n\n\n
  13. Hydraulic oil ratings<\/a><\/li>\n\n\n\n
  14. Hydraulic oil analysis<\/a><\/li>\n\n\n\n
  15. Why is hydraulic oil analysis important?<\/a><\/li>\n\n\n\n
  16. Hydraulic oil temperature range<\/a><\/li>\n\n\n\n
  17. Viscosity of hydraulic oil vs temperature<\/a><\/li>\n\n\n\n
  18. Hydraulic oil viscosity index<\/a><\/li>\n\n\n\n
  19. Hydraulic oil viscosity explained<\/a><\/li>\n\n\n\n
  20. Hydraulic oil viscosity conversion chart<\/a><\/li>\n\n\n\n
  21. Hydraulic oil grades<\/a><\/li>\n\n\n\n
  22. Hydraulic oil flash point<\/a><\/li>\n<\/ol>\n<\/div>\n\n\n\n
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    \"Viscosity<\/h3>\n<\/div>\n\n\n\n
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    <\/a>What is hydraulic oil?<\/h2>\n\n\n\n

    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.<\/em><\/p>\n\n\n\n

    At Crown Oil, as a hydraulic oil supplier<\/a>, we deal with 99% of mineral-based hydraulic oils.<\/p>\n\n\n\n

    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.<\/p>\n<\/div>\n\n\n\n

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    Main difference between synthetic and mineral-based hydraulic oil<\/h2>\n\n\n\n

    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.<\/p>\n\n\n\n

    Synthetic oils can be formulated to impart superior physical properties in comparison to mineral oils, for example, high-temperature performance, biodegradability and oxidation stability.<\/p>\n<\/div>\n\n\n\n

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    <\/a>How do hydraulic systems work?<\/h2>\n\n\n\n

    The key role of hydraulic oil in a hydraulic system is to transfer power from one end of that system to another end through and the various hydraulic components.<\/p>\n\n\n\n

    When an external force is applied to the non-compressible hydraulic fluid – usually from a piston within a cylinder – the oil is pushed through the hydraulic system and ultimately produces a force on another part of the system. This results in a movement or action.<\/p>\n\n\n\n

    Usually applying force to material results in compression, so you may be wondering whether hydraulic oil is compressible or not, but a key property of hydraulic fluids is that they must be non-compressible.<\/p>\n\n\n\n

    \u2018Non-compressible\u2019 means that the fluid cannot be compressed. Liquids are compressible to some degree<\/a>, but it is incredibly negligible and not considered for our guide. In contrast, gases are compressible, and so are not used in hydraulics.<\/p>\n<\/div>\n\n\n\n

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    \"Hydraulic<\/figure>\n<\/div>\n\n\n\n
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    <\/a>What is hydraulic oil used for?<\/h2>\n\n\n\n

    Due to the vast array of uses for hydraulic fluid and industrial hydraulic oil, they are used in many applications across every industry.<\/p>\n\n\n\n

    Here are 10 examples of equipment and machinery which use hydraulic oil:<\/strong><\/p>\n\n\n\n

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    1. Air tools<\/strong> – Air tools and air compressors require high-pressure hydraulic oil which contains anti-wear additives for protection.<\/li>\n\n\n\n
    2. Aircraft (aviation)<\/strong> – 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.<\/li>\n\n\n\n
    3. Automotive lifts<\/strong> – 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.<\/li>\n\n\n\n
    4. Cruise ships and the marine industry<\/strong> – If you\u2019ve been lucky enough to go on a cruise ship then you\u2019ll 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\u2019s 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.<\/li>\n\n\n\n
    5. Forklift trucks<\/strong> – The hydraulic system within forklift trucks and stackers is important to help power the incredibly strong forks which need to lift some super-heavy goods.<\/li>\n\n\n\n
    6. Log splitters<\/strong> – 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!<\/li>\n\n\n\n
    7. Skid steers (skid-steer loader and skidsteer)<\/strong> – 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.<\/li>\n\n\n\n
    8. Snow ploughs (snow plows)<\/strong> – 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.<\/li>\n\n\n\n
    9. Tractors<\/strong> – 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.<\/li>\n\n\n\n
    10. Wright standers<\/strong> – 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.<\/li>\n<\/ol>\n<\/div>\n\n\n\n
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      <\/a>Hydraulic fluid properties<\/h2>\n\n\n\n

      The properties and characteristics of any hydraulic oil are vitally important to the capability of your hydraulic system to work within the operating conditions you need to use it in. This is especially true of industrial or commercial hydraulic oils.<\/p>\n\n\n\n

      So, for a hydraulic oil to be useful it needs to have the below properties:<\/strong><\/p>\n\n\n\n