On Wednesday, 10 April 2013 05:24:46 UTC+1, Larry Stoter wrote:
I have just got a small chain saw for the first time.



The instruction say I need to get chain saw oil, to lubricate the chain

during operation.



Do I really need a specific oil or is ordinary car gear box oil going to

work just as well?



Larry

Gear oil is too thick
Old engine oil is carcinogenic and in any case is bad stuff to spray around.
Proper chain oil isn't going to break the bank and it's formulated for 'anti-fling' properties as well as being a good lube for the job.
You can get 'standard' mineral based formulations but increasingly for professional use folks are starting to change to bio-degradable vegetable based products. But not cooking oil etc it congeals.
See Janet's comments further down. These machines can do you a very severe injury or worse. Also a wrong cut (even with a small saw) can bring something down on you or onto something you don't want damaging.
So at the very least get some training or failing all else read, re-read the manual many times and don't try anything clever until you know how the saw feels and behaves in your hands.
Buy personal protective clothing - cut proof chainsaw boots, gloves and trousers or leggings and helmet with mesh visor and ear defenders.
Learn how to sharpen it and keep it sharp.

Rod