Recycled steel if you can find any.

[Toolmaker51]

Unfortunately the mill and lathe didn't get a clean down today maybe tomorrow I use ordinary furniture polish it is brilliant and of course cheap

I'm no chemist. However there evidently is chemistry at work where non-petroleum oils work to dissolve grime on machine tools. In the case of handcleaner & furniture polish, citrus additives seem central to satisfactory results.

[Okapi]

Citrus based solvents are the most active for cleaning in my opinion too, but they have a certain dangerosity, for me due to the chemical products used in their culture, we do be careful and always have nitril gloves when using them.
I use a solvent like that to take out paper glued on surfaces and it's literally magic.

[jdurand]

If anyone is in the SF Bay Area, I have a bunch of my raw materials that need a new home. I've got long sticks of some things like angle steel, some tube, and of course shorter stuff and plastic.

[Captainleeward]

Some one has been in the sand box again sandy cheeks....Cap. I'm not saying who.....

[Toolmaker51]

Unlike the past, remnant and bar-ends are rare to find on the open market. Steel scrap isn't $0.25 or 0.30¢ a pound anymore either.

[Philip Davies]

Please find me some!