If you are going to post speeds you should also include the use of oil for keeping the bit cool while drilling.
Hi Folks.
When it comes to 300 series stainless I often slow things down a good bit.
Most often I use an animal fat such as bacon grease to do my tapping and drilling.....sometimes when I'm in a pinch I will use a can of vegetable shortening such as Crisco.
I would stay away from things such as WD-40, motor oil or even burnt /used motor oil, its more of a lubricant than a cutting oil.
Years ago...up until about the mid 80's or so they use to use 1-1-1 triclorethelyne ( spelling?) in tapping fluids such as "Tap-Magic", but did away with it due to cancer causing possibilities, and many mfg's of cutting fluids saw the writing on the wall with regulations and started switching over to more eco-friendly substiutites....and some ( but not all) of the tapping fluids out there are nothing but over glorified biodegrable animal byproducts
the tapping and cutting fluid which appears to be a black oil ( sulfurized cutting oil) is good to use, but it has a lot of sulfur and chlorine in it to assist in tapping/drilling...and will stink you out of a shop if goes to letting off a little smoke, so keep your drill bits sharp and slow them down a bit further to keep the smoke from curing you like a ham.
Come to think about it, they probably used animals fats to do their tapping in the 17 & 18th centuries... try a little bacon grease next time or vegetable shortening... both are in a semi-solid state....just smear it on the drill or tap. I never buy those" fancy-smancy" tapping fluids anymore....I have probably tapped a million and two holes in my lifetime thus far and bacon grease or " Crisco" is up top with the best
But dont go eating a bunch of bacon to get the tapping fluid....that stuff could be just as bad on your arteries as 1-1-1 tricloethelene was to people's health.
All the best,
Gavin
