On Jul 4, 6:45*pm, Tom Quackenbush wrote:
* My "lat" can of cutiing oil wandered off, so I went to the local
Borg to buy some more. All that they had was pints of "dark" thread
cuttiing oil (Oatey 30203), so I bought that.

* I'll be using it for cutting or drillling *iron/steel.

* What's the difference? For Harry homeowner, does it matter?

R,
Tom Q.l

The dark stuff has more sulfur in it, eases cutting threads on steel/
iron pipe with pipe dies. Also reacts with aluminum, so don't use it
for cutting that. A good choice for dabbing on a steel workpiece.
Expensive and messy for coolant setups, have seen it used, though.
When the workpiece gets hot, it smokes, other inhabitants may not
appreciate it. I use it all the time for drilling and tapping harder
steels, like guns.

Usually the clear cutting oils rely more on chlorine, kind of does the
same job, not as effective, in my opinion, for hand uses on hard
steels. This stuff also reacts with aluminum, usually more
vigorously.

Lard oil is another good choice, should you find an old-timey hardware
store that carries it. Can be found in some of the "green" mixes,
it's biodegradeable.

Stan