Cutting oils, or fluids as they are sometimes referred to, are designed to aid metal cutting processes by cooling the workpiece and the saw blade while cutting. If the blade or material get too hot during cutting, drilling or similar, it’ll compromise the finished product, blade life and in extreme circumstances, the machine. They also help to clean off swarf from the workpiece and improve the surface finish. Choosing the wrong cutting fluid can have costly consequences for your business.

TYPES OF FLUIDS AVAILABLE

Plain / Straight Cutting Oils

A plain cutting oil is an oil derived from petroleum or other origin used straight or in combination. Mineral oils – which are based on petroleum, tend to be the most popular choice for metal cutting applications but are generally restricted to lighter duty work. Many of these oils are enriched with additives to increase their effectiveness. These are mainly animal fats/oils, vegetable oils or marine oils, however, organic materials are prone to developing unsafe bacteria cultures and unpleasant smells. The other options are chemical additives such as Sulphur, Chlorine and Phosphorous, which provide solid film lubrication through chemical reactions with cutting surfaces.

Soluble Cutting Oils

A slight change in formulation from straight cutting oils, soluble oils contain a suspension of animal/vegetable oils or the chemicals mentioned above in water to combine the cooling and lubrication properties needed. Compared to straight oils, soluble fluids have better cooling abilities and are generally cleaner, cost less and have a higher bacteria resistance, however, rust can be an issue and lubricating properties are reduced in favour of cooling. Another point to mention is foaming of the fluid – anything with water can foam within the delivery system.

Synthetic and Semi-Synthetic

Synthetic fluids consist of a chemical solution (Sulphur, Phosphorus and Chlorine), fully synthetic fluids contain no oil of any kind, while semi-synthetic fluids contain some small quantities of mineral oils and oil additives to enhance the lubricating function. Along with giving more visibility when processing metals, better tank life, reduced toxicity, the much lower chance of bacterial growth and easier maintenance.