Welcome to the Metrol Blog

Welcome to the Metrol Blog, your go-to source for the latest insights, tips, and updates in the world of industrial and heavy-duty oils. Here, we share expert knowledge, industry trends, and practical advice to help you get the most out of our high-quality lubrication solutions. Whether you are looking to improve the performance of your equipment, stay informed about the latest innovations, or learn more about best practices in the field, our blog is designed to keep you informed and engaged. Join us on this journey to excellence and discover how Metrol and M-Trade continue to lead the way in superior lubrication solutions.

Hydraulic Oil

What is hydraulic oil?

Hydraulic oil is a specialized fluid designed to transmit power within hydraulic systems. It converts mechanical force into hydraulic energy, facilitating the movement of components like hydraulic cylinders and motors.

What is the importance of hydraulic oil?

Transferring Hydraulic Energy: It efficiently moves energy from the pump to various system components.

Lubricating Moving Parts: It minimizes friction and wear, thereby extending the lifespan of system parts.

Cooling and Heat Dissipation: It helps in cooling down system components and removing excess heat generated during operation.

Corrosion Protection: It safeguards metal parts against corrosion and rust.

System Cleaning: It assists in purging impurities and debris, ensuring optimal system performance.

What are the specifications of hydraulic oil?

The selection of hydraulic oil is based on several specifications, which include:

  • Viscosity: A measure of the oil’s flowability at different temperatures.
  • Anti-Wear Properties: Resistance to wear for enhanced component longevity.
  • Anti-Oxidation: Prevention of sediment formation and odor development.
  • Anti-Aging: Chemical stability over time.
  • Anti-Foaming: Reduction of foam and bubble formation.
  • Rust Protection: Shielding metal parts from corrosion.
  • Thermal Stability: Performance stability at high temperatures.
  • Detergent Properties: Prevention of deposit and dirt accumulation.
  • Additional Features: Some oils include additives like antifreeze or corrosion inhibitors for improved performance under specific conditions.

What are the types of hydraulic oil?

  1. Mineral Oil-Based Hydraulic Fluids: These are the most common, with additives tailored to application needs. They are classified under DIN 51524 standards into categories like HL, HLP, and HVLP, each with distinct properties regarding corrosion protection, wear resistance, and viscosity-temperature relationship.
ClassificationsProperties
DIN 51524ISO 6743-4
HHHNon-inhibited solvent-refined mineral oils (-10°C to 90°C)
HLHLRefined mineral oil with improved anti-rust and antioxidant properties (-10°C to 90°C)
HLPHMHL-type oils with improved anti-wear properties (-20°C to 90°C)
HVLPHVHM-type oils with improved viscosity/temperature properties (-35°C to 120°C)
HLPD-Similar to HLP, but with additives to enhance particle transfer (detergent effect) and dispersion capacity (ability to carry water) and active components to increase corrosion protection.

2. Fire-Resistant Liquids: These fluids are categorized based on their water content and base materials, offering flame resistance and suitability for a range of temperatures and pressures. Types include HFAE, HFAS, HFB, HFC, and HFD, each with unique characteristics and applications.

ClassificationsProperties
HFAEFire-resistant oil-in-water emulsions with a maximum 20% weight of combustible materials
HFASFire-resistant solutions of a chemical in water with a minimum of 80% water weight
HFBFire-resistant emulsions of water in oil
HFCFire-resistant fluids of water-polymer solutions with a minimum of 35% water weight
HFD

HFD-R: Synthetic fire-resistant fluids that are phosphate-ester-based

HFD-S: Synthetic fire-resistant fluids that are chlorinated and hydrocarbon-based

HFD-T: Synthetic fire-resistant fluids consisting of HFDR and HFDS blends

HFD-U: Other types of synthetic fire-resistant fluids

How to select the Right hydraulic oil?

The choice of hydraulic oil should consider:

  • System Requirements: Operating pressure, temperature exposure, environmental conditions, and lubrication needs.
  • Viscosity: Selection of an oil with suitable viscosity for the operating temperature.
  • Manufacturer’s Instructions: Adherence to specifications recommended by the system or machine manufacturer.
  • Additional Specifications: Consideration of features like corrosion or aging resistance.
  • Expert Advice: Consultation with hydraulic professionals for guidance.

Industrial Greases

What are industrial greases?

Industrial greases are semi-solid or solid lubricants made by combining heavy oil with a thickener (often soap-based) and additives. This combination provides several advantages over oil alone:

Thicker consistency: Greases adhere better to surfaces, offering a more durable lubrication layer.

Higher viscosity: Greases resist flow better than oil, staying in place under pressure and at higher temperatures.

Components of Industrial Greases:

  • Oil: Most industrial greases use mineral oil for its high performance and availability.
  • Thickener: This gives the grease its structure. Common thickeners include Sodium, Calcium, Lithium, Aluminum, Clay, and Polyurea soaps.
  • Additives: These enhance specific properties like extreme pressure resistance, rust prevention, or anti-wear capabilities.

Properties of industrial greases?

  • Dropping Point: This is the temperature at which a grease transitions from a semi-solid to a liquid state under specific test conditions. It's an indicator of the grease's ability to withstand high temperatures without thinning excessively. A higher dropping point generally signifies better suitability for hot environments.
  • Degree of consistency (NLGI Grade): The National Lubricating Grease Institute (NLGI) classifies greases based on consistency. A lower NLGI number indicates a thinner, more fluid grease (e.g., 000), while a higher number signifies a thicker, more solid grease (e.g., 6).
NLGIAppearanceDescription
000FluidCooking Oil 
00SemifluidApple Sauce 
0Very SoftBrown Mustard 
1SoftTomato Sauce 
2

Normal Grease

Peanut Butter 
3FirmVegetable Shortening 
4

Very Firm

Ice Cream 
5HardSmooth Pate 
6Very HardCheddar Cheese 

Advantages of industrial greases?

  • Better adhesion: Greases stick well to surfaces, providing a long-lasting lubrication layer. Improved insulation: It offers superior insulation properties, which helps protect the machines.
  • Enhanced protection: Greases guard against corrosion, wear, and tear caused by friction.
  • High-temperature operation: They can withstand higher temperatures than oil, making them suitable for demanding environments.
  • Noise and vibration reduction: Greases help dampen noise and vibrations, extending equipment life and creating a quieter workspace.

Types of industrial greases?

Calcium Grease

versatile grease for various applications, including industrial, automotive, and agricultural. It offers good water resistance and rust protection, making it ideal for low-temperature environments.

  • Lithium Grease

Another multi-purpose option is known for its stability, durability, and high performance. It provides excellent protection against corrosion, oxidation, and extreme temperatures. Lithium grease is water-resistant and offers superior lubrication under extreme pressure.

  • Bentonite Clay Grease:

This clay-based grease (also known as bentonite grease) offers superior resistance to temperature changes, wear and tear, and water. It's ideal for heavy-duty applications due to its improved shear stability.

  • Graphite Grease:

Contains graphite particles as a solid lubricant, offering excellent anti-wear properties and high-temperature resistance. This grease is commonly used in slow-moving, extreme-pressure applications.

  • Moly Grease:

Molybdenum disulfide (MoS2) is added to this grease for exceptional extreme pressure (EP) performance. It's well-suited for heavily loaded bearings and sliding mechanisms operating under extreme pressure and shock loads.

  • Lithium Complex Grease

possess many of the properties of simple lithium soap grease step further. It incorporates a complexing agent alongside the lithium soap thickener resulting in improved performance over standard lithium grease. It offers superior high-temperature resistance, water washout resistance, and shear stability, making it suitable for demanding applications.

  • Calcium Sulfonate Grease: Provides excellent water resistance and extreme pressure resistance. This grease is a good choice for wet environments and applications with high shock loads.