Metalworking Fluid: Definition, Classification, and Selection

Metalworking fluid, also known as coolant, cutting oil, or cutting fluid, is a specially formulated liquid made from base oil and additives. It is used in metal machining and cutting processes to cool, lubricate, and improve machining precision and surface finish. The fluid reduces friction at the cutting point, helping to prolong tool life. Additionally, cutting oil assists in flushing away metal chips from the workpiece and cutting tools, reducing the chances of machining errors caused by chip accumulation. It also helps prevent thermal deformation of the machine due to heat generated during the cutting process.

1. Classification of Metalworking Fluids

Metalworking fluids are generally classified into two main types:

1.1. Neat Cutting Oils (Straight Oils)

Neat cutting oils, also known as non-water-soluble cutting oils, are used without dilution. These oils are typically applied in machining operations where low heat generation or high lubrication performance is required.

1.2. Water-Soluble Metalworking Fluids

Water-soluble metalworking fluids, also known as emulsifiable cutting oils, are types of cutting fluids that require mixing with a solvent (usually water) to form an emulsion before use. These fluids are commonly used in machining processes that generate a high amount of heat and require lower levels of lubrication.
Depending on the specific machining requirements and the manufacturer's recommendations, the oil-to-water mixing ratio may vary.

2. Notes on Selecting Metalworking Fluids

The first and most important step is to refer to the machine or equipment manufacturer’s recommendations—what type of metalworking oil is suggested, under what brand, and with what specifications?

You can also opt for high-quality products from reputable global industrial oil brands that are already present in Vietnam. One such example is SHL Lubricants (formerly known as Samhwa Lube Oil), a leading Korean lubricant manufacturer with over 50 years of proud history in the lubricant industry.
We are confident in being the top metalworking fluid brand in Korea, currently holding over 86% of the domestic market share.