Are You Using the Right Amount of Cutting Fluid?

| BlackHawk Team

CNC milling machine getting washed by master fluids

When it comes to coolant maintenance, one of the most common mistakes we see our customers make is running machines with the wrong fluid concentration. For coolant to work efficiently, it needs the right concentration amount, which is between 5%-10%. It’s a simple factor to control, yet it’s a problem we see over and over.

Keep in mind that fluid manufacturers have designed their products to be used at that 5%-10% concentration ratio. More is not better, and you won’t save money by using less. You also want to make sure you’re using a high-quality coolant. BlackHawk sells several top-line oils. Master Fluid, for example, is one of our recommended brands. Master Fluid Solutions products are environmentally sound and, when used in conjunction with Master Fluid Solutions fluid management systems, are highly durable and stable. You can find Master Fluid online through BlackHawk.

Try the Master Fluids Low-Foam Synthetic Fluid Five-Gallon Pail or 54-Gallon Drum at Also try Master’s water-clear synthetic coolant CoolPak Five-Gallon Pail or 54-Gallon Drum.

No matter how good the coolant is, if it’s launched too lean, you shorten your tool life and run the risk of rancidity. Most cutting fluids are formulated to cut bactericides and control microbial growth, but they can’t do those things if the concentration is too low. When the concentration is too low, it doesn't have enough biocide – which is what keeps bacteria away – and it becomes rancid due to chemical decomposition. The fluid will put off a terrible odor. You’ll end up having to remove all the fluid and replace it with new coolant. The rancid oil could possibly become hazardous waste and may lead to a more expensive disposal fee.

In addition to a shorter fluid life, you’re also shortening your tool life. Cutting fluids are a key part of the machining process. They reduce the effect of friction and carry heat away during machining operations. The proper use of coolants will lower heat and friction and protect the microstructure of metals.

We know cutting tools are the biggest expense for most manufacturers. Anything you can do to save on the cutting tool budget is a huge advantage. Buying the right coolant and using it at the recommended concentration can increase your tool life by at least 5%. In some cases, we’ve even seen an increase of 10%. If you have a tool budget of $1 million, that’s $50,000 or even $100,000. The price of replacing a rusted machine can be even greater. When concentration levels are low, the components in the fluid that provide corrosion protection are insufficient to protect the metal surfaces. Even if the machine doesn’t have to be replaced, it can be an expensive repair.

It’s not hard to figure out whether you’re in that 5%-10% sweet spot with your fluid concentration. We recommend using a refractometer. It’s relatively inexpensive and doesn’t take up any storage space. You just put a drop of fluid in and hold it up to the light. The refractor will measure the light passing through and determine the consistency. Some refractors come with digital LCD displays to make them easier to read.    

For additional questions about Master Fluid Solutions sold by BlackHawk Industrial, contact your BlackHawk rep or call us at 855-610-1001. We’re ready to help. Our mission is to provide innovative, value-added services and products that reduce our customer’s total cost. Feel free to contact us at [email protected] for more information.