Hi, I am going to "break the glaze" on a big block auto engine and am wondering if the light cutting tread cutting oil I have is ok to use withhoneing stones. A friend of mine says the shop he used to work in just used #10 motor oil for years for this. I have worked with dark tread cutting oil for many years on pipe and know you can't use motor oil for pipe thread cutting [tears up the threads]. Went to lots of sites to see what the difference between cutting oil and honeing oil is. Both seem to have sulphur and clorine in them [the old stuff anyway] but I still don't know what the difference is. Sooo- I thought I would ask this group if they would tell me the difference, in laymans terms hopefully. any information would be appericated, Tallemani at comcast dot net. Tom.