Optimizing the Use of CNC Coolant-Considerations for CNC Coolant

Find the Right Coolant Concentration

Insufficient coolant concentration can lead to some problems, including bacterial development, shorter tool lives, and corrosion of the machine and workpiece.

However, if the coolant concentration is too high, you can notice any of the following:

• Foaming

• Fewer lubricants

• Discarded coolant

• Reduced tool life due to residue formation

• Machine and machined component stains

• Toxicity

At the beginning of each day, machinists should check the coolant and maintain a suitable level of focus. Hand refractometers are great for controlling and monitoring cutting fluid amounts. Keep in mind that evaporation, splashing, and misting can cause machine coolant concentrations to fluctuate by up to 20% every day. To understand how the coolant system functions and how much the concentration levels vary from day to day; it is necessary to keep a daily diary of concentration levels for each CNC machine.

To increase the lifespan of the coolant, the cutting tools, and your CNC machine, it's critical to choose the right coolant for your machine and the metals you're machining and to maintain the specified concentration levels.

CNC Coolant Concentration Chart

Below is a coolant concentration chart containing variations in the CNC coolant concentration levels:

Material	Milling	Drilling	Tapping	Turning
Aluminum	Soluble oil (96% water) or mineral oil	Soluble oil (70-90% water)	25% sulfur-based oil mixed with mineral oil	Mineral oil with 10% fat (or) soluble oil
Brass	Soluble oil (96% water)	Soluble oil	10-20% lard oil with mineral oil	Mineral oil with 10% fat
Bronze	Soluble oil	Soluble oil	30% lard with mineral oil	Soluble oil
Alloy Steels	10% lard oil with 90% mineral oil	Soluble oil	30% lard oil with 70% mineral oil	25% sulfur base oil with 75% mineral oil
Cast Iron	Dry	Dry	Dry or 25% lard oil with 80% mineral oil	Dry
Malleable Iron	Soluble oil	Soluble oil	Soluble oil	Soluble oil
Copper	Soluble oil	Soluble oil	Soluble oil	Soluble oil
Low Carbon and Tool Steels	Soluble oil	Soluble oil	25-40% lard oil with mineral oil	25% lard oil with 75% mineral oil

Change the coolant in CNC machine

The interval for changing CNC machine coolant can vary depending on factors such as the machined material, coolant type, and operating conditions of the CNC machine. However, as a general rule of thumb, most CNC machine manufacturers recommend changing the coolant every 6-12 months.

Eliminate bacteria in CNC machining coolant

Bacterial growth in CNC machining coolant can be prevented or stopped by injecting ozone directly into the coolant. Ozone effectively kills viruses, bacteria, molds, and eliminates odors in the coolant sump.

Foaming in CNC coolant

Foaming in CNC coolant is primarily caused by the lack of minerals in the water supply. It's advisable to check the water hardness using Hardness Testing Sticks to address this issue.

Conclusion

CNC machine coolants play a vital role in achieving optimal efficiency in a CNC shop by reducing heat build-up, lubricating cutting tools, and preventing discoloration and failure in various machining processes such as CNC milling, turning, or drilling. If you require assistance in determining the ideal lubricant type for your CNC machines, do not hesitate to reach out to us at STS. Our team of professionals is always ready to help.