Picked up this link :- **LINK** via another forum. 25 pages worth.

Has what seemed to me to be a fairly nice overview of lubrication fundamentals the difference in oil types and their use on machines. I found the speed / clearance / viscosity coverage of particular interest as I've never had any useful understanding as to what oil to use when. Most texts I've seen being either very application specific, very technically complex or both (wiv extra maths!). The originators main business is in consultancy and training to get the most out of oils in industrial plant applications so rather a lot on cleanliness and filtration. Mostly ho-hum for folks like us.

One thing I hadn't appreciated is that the anti-wear additives in the ISO hydraulic oils often used for general lubrication in our sizes of machine tools are irrelevant for normal rotting shafts, bearings et al. They are included for protection when things start up from rest or come to a stop as the oil film is disrupted at such times. Clearly important for hydraulic rams and the like which tend to do a lot of starting and stopping. Not so much on machines where things are either stopped or spinning for significant periods.

Clive.