Synkool HD is a premium quality, water-soluble, synthetic coolant developed for medium- to heavy-duty turning, milling and grinding of ferrous metals, as well as grinding and light-duty machining of aluminum and copper alloys. It contains a biocide and mixes easily with soft or hard water to form a high-quality synthetic metalworking fluid that provides excellent cooling properties and lubricity for maximum tool life and high-quality surface finishes on the machined parts.

Synkool HD is formulated to provide an optimum balance of lubricity and detergency for high-quality finishes on machined parts and for overall machine cleanliness. It is ideal for use in machine sumps, as well as in once-through applications because it is highly resistant to microbial and bacterial degradation that causes rancid odors. It forms a clear, amber-colored solution that permits easy observation of the machining operation. It has high lubricity to help minimize tool wear and prevent particle agglomeration. Special inhibitors help protect metal surfaces against rust and corrosion.

Synkool HD does not contain active sulfur, nitrites, phenols or diethanolamine (DEA).
Unit of Measure


Density @ 15.6 ºC (60 ºF)

N/A 1.05 g/cm³8.73 lbs/gal
Color1 N/A Amber

Boiling Point

N/A 100 ºC212 ºF

Freezing Point

N/A 0 ºC32 ºF

pH 5% (1:20) Dilution

N/A 9.0

Water, Wt

N/A 60 %
Chlorine, Wt.2 N/A 0.07 %

Sodium, Wt.

N/A 0.20 %

Recommended Concentrations, Synkool HD in Water (Volume %)


Carbon Steel
Operation Cast Iron High Alloy Steels Tool Steels
Drilling, Milling, Turning 4 5 5
Light-Duty Broaching, Form Milling, Reaming, Sawing, Tapping 5 5-6 5-6
Grinding 3 3 3

Refractometer Reading


Dilution Ratio 1:10 1:15 1:20 1:25 1:30
Reading 4 2.4 2.1 1.7 1.3


N/A Synkool HD is recommended for medium- to heavy-duty machining of ferrous metals and metal alloys with water hardness greater than 350 ppm. Typical applications include:

  • Broaching (light-duty)
  • Drilling
  • Grinding
  • Milling
  • Reaming
  • Sawing
  • Tapping
  • Turning
Synkool HD also is recommended for light-duty grinding and machining of aluminum and copper alloys.



  • Excellent cooling and lubricating properties
  • Helps extend cutting tool life
  • Reduces grinding wheel wear
  • Good surface finish
  • Excellent rust protection
  • Noncorrosive to non-ferrous metals
  • Resists bacterial degradation
  • Transparent for good visibility of the machining operation
  • Mixes easily with water
    Note: When mixing, always add Synkool HD to water; never add water to Synkool HD. Typical concentrations (Synkool HD in water) range from 3% to 6% depending on the machining operation, type of metal, and water hardness. Coolant concentration may be monitored with a refractometer.

Health and Safety Information

N/A For recommendations on safe handling and use of this product, please refer to the Material Safety Data Sheet via

Ordering Information

Package Type

N/A 55G RD

Pricing Information

N/A Price/Gal

Shipping Note

N/A Shipping will be quoted upon receipt of your order.

  • 1 Test-Visual
  • 2 From the Biocide