MTFCA Forum

I have always used oil-based when reaming. I'm reaming valve guides and decided to try water based. The company I work for uses water based in our cutting machinery. I'm not happy with progress so far. I ruined my reamer when I hit a hard spot in the casting. Before I finish. What do you all prefer and why?

Old-fashioned oil-based thread cutting oil ought to work.
If you hit a sand inclusion in the block, it wouldn't matter much what lubricant you used.
I'd guess water-base lubricants are meant for modern, insert-type cutting tools. Tool steel cutters probably work best with an oil base lube.

Cast iron= dry.

Three years ago I reamer the valve guides dry and had no problem. Definitely don't use motor oil. It's important to control the reamer alignment.

Art Mirtes

Our machinist used water soluble oil. Oil that would mix with water. It would circulate through the machine and pass through a strainer. It went much farther and was just as good as regular lubricating oil.

Dan McEachern wrote: ↑

Tue Feb 13, 2024 2:15 pm

Cast iron= dry.

Dan, Scott Conger told me the same thing. I was unaware that cast iron should be dry. Thank you for your input.

Well there it is in my Machinery's Handbook. Cast iron should be dry. I should have looked there first. Thanks to all.

Do you use cutting oil when reaming bronze bushings or can you ream them dry?

Bronze should have soluable oil.

OK I'm not very bright. What is soluable oil?

Soluble Oil is a chlorine-free, water miscible metalworking fluid designed to emulsify easily and form a long-lasting, stable emulsion when mixed with water

Water soluble oil. Oil that mixes with water. Designed for providing lubricant and cooling properties to machine work that would overheat without it. Makes the lubricating oil thinner and allows it to go farther making the job more economical.


Just one example. There are all types of brands.

OK Thanks a lot for telling an old dummy guys. I always learn something on this forum.

I agree usually cast-iron is cut dry. But sometimes I would use something like WD-40 or PB blaster.