Outside of tooling and materials, the most important inventory item for a machine shop is machine coolants. As the label implies, coolants are responsible for maintaining equipment within an optimal temperature range during operation. Not only does this prolong the machine’s life and keep performance reliable, but it improves machine safety, reduces some related costs, and promotes better productivity and product quality.
The latter is especially true when working with complex materials where precision is paramount for reliable outcomes – such as super-alloys or refractory metals.
Different machines have different, even unique parameters and requirements — including various types of coolants. Machining coolants come in a several forms, each with its own considerations and applications.
Types of coolants
Straight Oils. Not unlike standard oil, these coolants are thick, concentrated formulations that contain a numerous ingredients — primarily lubricants. Their sole purpose is to provide lubrication for the machining process, to reduce friction, but they also sacrifice some cooling properties to do so.
Solubles. Water-soluble and cutting fluids offer an excellent middle-ground and are among the most common types of general-purpose coolants. They lubricate and reduce heat, but require more maintenance — fungus and bacteria can grow in a dirty sump.
Synthetics (fluids.) Synthetics are designed specifically for cooling and contain no mineral or tramp oils. This results in a cleaner solution with remarkable cooling properties. The downside is these are not a good choice when lubrication is essential.
Semi-synthetics (fluids.) Offering solid cooling properties — and reliable lubrication via a solution with less oil, less odor and a cleaner experience — you can use semi-synthetics for just about any machining purpose. However, they may not be as effective in extreme situations.
Alternatives. Machining coolants may come in other forms too, such as:
• Gels
• Pastes
• Aerosol
• Pressurized CO2 coolant (carbon dioxide)
Every shop should have at least one type of each coolant available, depending on the active machines. Moreover, keeping the supply stocked and steady is crucial to an optimal, delay-free operation.
Air-based coolant. Standard air-based coolant — not necessarily pressurized — is another common form for machine shops to stock. It works best for projects involving sensitive materials like plastics because they cannot withstand extreme treatments that may incur thermal shock.
A problem with standard air is it does not offer reliable cooling properties, even compared to something like water. It doesn’t provide any lubrication either.
Still, it’s always a good idea to have air administration hardware available in the shop. It can be a can of compressed air, an air compressor, or a proprietary feature attached to machining equipment.
Additional supplies
Depending on the type of machining coolant and the administration method, it may be necessary to have additional supplies on hand. For example, you’ll need a steady water supply from a hose and nozzle, nearby tanks, or reclaimed sources with water-based coolant. The same is true for oils, synthetics, and other fluids.
As a real-world example, nitrogen is an exceptional form of coolant for aluminum extrusion equipment, but it’s an inert gas that is not freely available everywhere. You’ll need to have a well-stocked inventory in the shop and a steady supply at the ready from a partner or vendor for when you eventually run low.
Administration method
Every machine requires unique care, and it is critical to know how and when to apply the machining coolants and what administration method they need. You can automate the process or do it manually, with the three standard methods being air, mist, and flood.
More modern and advanced machines typically handle the administration process without any manual input. For example, a drill might spray the material with water or machining coolant as it’s doing the work. There’s no question this is a much safer method, but it also can create quite a mess.
In rare cases, maintenance teams may need syringes, pouring containers, and even personal protective gear when the machining coolant needs direct application to a surface or component. This extra gear is certainly something to consider and have on hand before working with shop equipment. It’s also necessary for keeping workers safe on the assembly line.
Coolants in the operation
You can run a machine without coolant — or the proper type — but chances are high the equipment will break down, fail, or become wholly damaged. As for the component or product you’re trying to produce with your machines, that’s not going to turn out so well either.
Simply put, machining coolants are at the heart of any machine shop and they’re just as important to the work as the hardware and raw materials. Even in operations that use dry machining versus wet machining, you’ll want to have at least some coolant on hand.
While some of this is a bit on the nose, there are other considerations you should make. For example, you should also stock additional equipment or tools your teams might need for applying coolant. That includes personal protective gear to keep them safe, like gloves, goggles, and full-body suits.
Coming out of this article, you should make sure you have all of the necessary coolants in your shop, with a well-stocked supply available for the foreseeable future. Also, you must ensure you have the appropriate sources handy to continue acquiring those supplies when they’re running low.
Keeping each machining coolant on hand can help you avoid disastrous results for your machines and products.
Emily Newton is the Editor-in-Chief of Revolutionized, an online magazine exploring the latest industrial innovations.
