What is Tramp Oil?

Tramp oil is a term that describes any unwanted hydrocarbon-based substance that contaminates machine coolant. This issue occurs mostly metalworking and manufacturing industries. Tramp oils can lead to numerous problems that affect work environment safety, production efficiency, and the cost control abilities.

The Unwanted Wanderers of the Machining World

The word “tramp” can have a few different meanings. One of the earliest definitions was that of an unwanted homeless wanderer. Similarly, in the machining world, tramp oil is a term for any unwanted hydrocarbon-based substance that migrates into the coolant of a machining center.

These oils can lead to numerous problems that affect the safety of the work environment, production efficiency, and the ability to control costs.

What Causes Tramp Oil?

How do these hydrocarbon-based substances find their way into a coolant sump?

There are a few different avenues.

Machining centers employ various linear motion and rotary motion components such as bearings, slides, ball screws, and spindles that require lubrication to function efficiently. Over time, these lubricants can find their way to the machining center platform where they mix with cutting fluid or coolant.

Another source of contamination is from the materials being processed in the machining center. Most stock metals have a corrosion prevention coating which is typically oil based. If the oil based coating is not removed prior to machining, it will end up mixing with the coolant.

Problems Associated with Tramp Oils

Tramp oil contaminated coolant causes a variety of problems if not separated and removed.

First, the coolant’s performance ability suffers. This is because oil in coolant reduces the coolant fluid’s ability to reduce temperatures effectively. Any oil that is present in the cutting fluid will promote heat generated by the tool, which can shorten tool life considerably.

Another consequence of oil coming in contact with a hot cutting tool is smoke. At high temperatures, the oil can become hot enough to burn. This can create unsafe working conditions.

When left alone, tramp oils that settle in coolant become breeding grounds for anaerobic bacteria. The oil essentially prevents oxygen from mixing with the coolant, which can promote the growth of anaerobic bacteria. Workers who come in contact with these bacteria are susceptible to contact dermatitis. The bacteria can also generate hydrogen sulfide gas, which emits an unpleasant rotten egg odor.