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Answers to Commonly Asked Questions

Should you have any further questions or concerns, contact our Laboratory @ 1-888-254-1919 or via email

What is a Refractometer?

A refractometer is a hand-held optical instrument, which can be used to measure the mix concentration of metalworking fluids. The refractometer provides a numeric reading by measuring the refractive index of the fluid mix.

How do you use a refractometer? (clear instructions)

A refractometer is a quick and easy method to roughly determine a metalworking fluids concentration. It must be "zeroed" to tap water (or the same source used from metalworking fluids) by following these steps:

  1. Lift the flap at one end of the refractometer, placing a drop of water on the glass underneath the flap.
  2. Turn the set screw (on top of the refractometer) until the interface line between the dark and light area viewed through the eyepiece (opposite end from the flap) is at the ‘0’ mark.
  3. Remove the water using a clean wiper and place a small amount of metalworking fluid on the glass underneath the flap.
  4. Read the number corresponding to the interface line between the light area and darker area.
  5. Multiply this number by the appropriate product refractometer factor and you will obtain your concentration.
  6. How do you calculate correct concentration from refractometer reading?

    The correct concentration is obtained from a refractometer by the following:

    • Concentration = refractometer reading X product factor

    Note: Each product has a different product factor

    What is a Refractometer Reading?

    A refractometer reading is the scalar reading on a refractometer obtained from a sample of metalworking fluid. The reading obtained occurs at the line interface between a brighter area and a darker area on a scale viewed through the eyepiece of the refractometer.

    What are Refractometer Factors?

    A Refractometer factor is a number, specific to each product which the reading found on a refractometer must be multiplied by to obtain the actual concentration.

    Why is my Refractometer Reading Hazy?

    A hazy refractometer reading is indicative of contamination, most likely oil, in the metalworking fluid system. Oil contamination causes the refractometer to read high, thus giving a false high concentration. Always read the refractometer, from the clear bottom of the hazy reading. This will help ensure the concentration remains in the proper range and not drop to a low level.

    Why put the Concentrate on the water?

    Most Milacron metalworking fluids are provided in a concentrated form to be diluted into water. When manually mixing metalworking fluids it is always recommended to add concentrate to the water. When adding concentrate to the water, the emulsifiers suspend the oil particles in the water and will form a stable mixture.

    Why is there bacteria?

    Bacteria is present everywhere in the world. There are thousands of species of bacteria present in the world and only a very small number of species are viable in metalworking lubricants. Many metalworking fluids do have microbicide agents present as part of the concentrate formulation and these are designed to prevent microbes from growing in the metalworking fluid. However, contamination from machine oils, rust preventatives and other sources can create an environment hospitable for bacteria growth. Also, combine this contamination with a low metalworking fluid concentration and bacterial growth can occur. To help minimize the potential for bacterial growth, maintain a recommended concentration and remove tramp oils from the system.

    What is the best environment to store MWF? Avoid freezing Avoid overheating

    The best environment to store metalworking fluid concentrate is at ambient room temperature. If a metalworking fluid freezes, separation of the components may occur. Excessive heat can also affect different components used in metalworking fluid concentrates. If product is frozen or overheated, contact our Laboratory @ 1-888-254-1919 or via email

    Why are MSDS only valid for 3 years?

    Material Safety Data Sheets (MSDS’s) are regulated by Canadian law under the Hazardous Products Act and the Hazardous Materials Information Review Act which was originally passed in 1988. These acts regulate the information needed on an MSDS and stipulates the expiry time for an MSDS. Material Safety Data Sheets are valid for three (3) years from the date of creation and must be updated before the three (3) years is over.