All You Should Know About Low Viscosity Silicone Oil

Silicone oil is renowned for its higher stability and non-toxic use at low texture tension and high spreading ability. Additionally, it is a composition of polydimethylsiloxane with simethicone and dimethicone So it is widely used in industrial and personal applications due to its unique properties.

Its properties are high lubricity, non-toxicity, and sturdy film strip formation. Silicone oils are needed to improve mechanical systems, satellites, films, and spacecraft lubrication performance. However, there is a high-viscosity and low-viscosity silicone oil.

Low-viscosity silicone oil is widely used in LED and sensor technology because of its refractive index and low molecular weight. Here we will discuss only low-viscosity silicone oil. Let’s know:

20cST Silicone Oil

What Is Low Viscosity Silicone Oil?

Low-viscosity silicone oil is an apparent, non-flammable, odorless, non-toxic, and non-corrosive transparent liquid. This low-viscosity PDMS oil is suitable for various cosmetic and personal care formulations. Mainly, you can temporarily use this oil’s essential components to transport functional substances.

Yet, you can use it as a low-viscosity siloxane. Still, it reduces the tackiness of the formulation, giving a unique silky skin feel. Pigments can decrease surface tension to disperse and promote uniform dispersion of solids.

Usually, this low-viscosity silicone oil is compatible with oiliness, storage stability, water resistance, and commonly used cosmetic ingredients.

Benefits Of Low Viscosity Silicone Oil:

  • Great heat stability
  • Great oxidation resistance
  • Low freezing point
  • Excellent weather resistance
  • Limited combustion
  • Low power points
  • Low surface tension
  • High dielectric power and compressibility
  • The intense heat of combustion
  • Low surface tension
  • Little change in viscosity as a function of temperature compared to non-silicone oils
  • Good resistance to increased shear forces


Silicone oils fulfill a wide variety of applications in numerous industries. They are suitable damping fluids, coating additives, plastic additives, plastic lubricants, electrical insulating fluids, and more. Also, you can use this oil in mechanical fluids, de-foaming, mold release, and electrical and textiles.

Similarly, you can use it as an active element in various furniture, automotive, leather, metal, and specialty polishes. Most importantly, you can use this oil in skin care products like makeup, hair care, cosmetics, etc.

Furthermore, it offers easy combing and detangling for dry and wet hair. Likewise, it also provides hair lubrication and a smooth, soft, and glossy feel.

20cST Silicone Oil:

Silicone oil is a liquid-based siloxane and part of the methyl silicone liquid system. The viscosity is 20cST, with a dielectric strength of ~ 14 kV/mm and a refractive index of ~ 1.4. Typically, its surface tension boosts with increasing viscosity. You can use this 20cST silicone oil in various usages like antiflatulent agents, lubrication, cosmetic additives, and dielectric coolants.

Silicone Damping Fluid:

Silicone damping fluid is a hydrophobic, transparent, odorless, and colorless linear 100% polydimethylsiloxane liquid. Besides, it also is a low-viscosity PDMS silicone oil, and its viscosity is 0.65cSt to 1 million cSt. These types of fluids are suitable for use in a broad range of industrial, aviation, military, oil, and gas exploration.

Undoubtedly, you also can use this product to damp variation, rotation, and motion. Without them, they are perfect for use in extremely low and high temperatures and high-pressure environments. If you can select the damping fluid properly, it can extend your equipment service life.

5cST viscosities are described by their broad service temperature range, high damping action, and excellent lubricity. Therefore, they are compatible with valve materials and O-rings gaskets.


Generally, you can use this 100% PDMS silicone dumping fluids in the following equipment:

  • Pressure gauges,
  • Pressure testing equipment,
  • Pressure instruments,
  • Temperature testing equipment,
  • Pumps,
  • Pipeline equipment,
  • Flow testing equipment,
  • Flow level sensors,
  • Electronic sensors, level controllers,
  • Rotary dampers,
  • Geothermal monitoring equipment, seismology equipment, etc.
20cST Silicone Oil

STO-50 Silicone Transformer Oil:

Adequately, STO-50 silicone transformer oil is a 100% polydimethylsiloxane silicone oil, and its viscosity is 50cSt @ 25°C. Notably, this transformer oil is designed uniquely for use as a dielectric fluid and coolant in high-voltage transformers.

Hence, this oil is described by its high dielectric power, low power point, high flash point, wide temperature range, etc. It’s a 100% PDMS silicone oil with no additives. Unlike traditional PDMS silicone liquids, STO-50 is dehydrated to a water content of <50 ppm to ensure maximum dielectric power.

Basically, this oil is an environmentally safe replacement for liquid-filled transformers. Hence, it’s best for transformers due to their high thermal stability.

Benefits Of STO-50 Silicone Transformer Oil:

  • High dielectric strength liquid
  • High flash point and high-temperature stability
  • Less viscosity change, less volatility
  • Chemically inert
  • Extensive thermal oxidation resistance
  • Low toxicity
  • Environmentally friendly transformer fluid Alternative to PCBs Longer service life than conventional transformer oils
  • Compatible with transformer insulation systems


Usually, you can use this transformer fluid as a:

  • The high-temperature laboratory bath fluid
  • Excellent dielectric coolant
  • High temperature / high-pressure fluid
  • The dielectric silicone bath fluid
  • Silicone damping fluid for electrical equipment and gauges
  • Refractive Index matching fluid
  • High-temperature calibration fluid
  • High-temperature fluid for flow control fluid


Typically, this transformer oil fulfills the International Electrotechnical Commission (IEC) 836 “Specification for electrical purposes. Subsequently, it also meets the ASTM D 4652 “silicon fluids for electrical insulation.

These standards cover physical and electrical properties, perfect for dielectric applications. Transformer oil has a fire point that exceeds the requirements of these documents. And it also has the lowest heat of combustion within the IEC 1100 class. You can find that the fluid is a more common fire hazard than other transformer oils.

Final Word:

Finally, low-viscosity silicone oil has low viscosity, inertness, and low power point, which provides low viscosity change with temperature. All these properties make them suitable for use in widely extreme low-temperature applications.

On the other hand, you can use this liquid in many instruments, sensors, gauges, vibration motion, and pressure. Ultimately, these features ensure that where they are used can offer the proper readings under the most adverse conditions.


Emon is Lubricants specialist who studied on Petroleum Engineering in UAE. He have more than 10 years experience on different kinds of lubrication including automobile troubleshooting.