I have used Oatey brand Dark Cutting Oil for years. I used to find it in the plumbing department at Home Depot and Lowes, with Lowes being a few dollars cheaper. I tried to buy some today and found that the cutting oil is no longer sold in the stores. You can order on-line with free delivery to your local store. I am wondering if they will discontinue carrying it altogether. This is a sulfonated and chlorinated oil and I find that it works well on the mill and lathe. I don't recall seeing any "yellow metal" cautions.
If you need some you might want to order it while the getting is good; 8 dollars and change for a quart.
If you need some you might want to order it while the getting is good; 8 dollars and change for a quart.