Keltec offers you specifically formulated oil for use in rotary screws. This is important, as the environment of a screw compressor (heat / compression / friction / high temperature) is very hard on oil and it's function. And accordingly, the compressor oil has additives that deal with these problems. The most common ingredients as base material is :

I) Petroleum
The lowest grade and usually has shortest life span, examples are :
- Atlas Copco GA 4K
- Gardner Denver Aeon 4000

II) Synthetic Hydrocarbon (PAO)
A very common base material: good lubricant with a good compatibility with seals and gaskets. Life span typically around 6000 hours, examples are:
- Atlas Copco GA8K
- Quincy Quin Syn

III) Diesters
Probably the most common base material which is a good lubricant and has a built in detergent action which will removed traces of petroleum or PAO types oils that may reside within the compressor from past lubricants (which will clog the separator): somewhat aggressive toward some oil ring and gasket materials. Usually the longest lasting lubricant in the range of 8000 hours.
Examples are:
- CompAir - CS 300 / 400
- Gardner Denver Aeon 8000
- Ingersoll Rand Coolant
- Kaeser S 100 / 150 / 320 / 460 / 680

IV) Polyglycol / Ester Mixtures
Examples are:
- Ingersoll Rand Ultra Coolant

In addition to the base material then, Keltec compressor oils contain additives that are designed to do the followings:
1. anti oxidation (acid)
2. high flash points (temperature at which material will ignite or burn)