Fowler 52-730-005-0, Chemical Etching Pen for Metal

This pen is great! It only works on some metal and surfaces, but when it works it's amazing. Works on almost all steels provided you get through the protective coatings.I believe this pen works by oxidizing the metal. So it relies on the surface of the metal you're writing on to be able to be oxidized. This also means if metal is coated with some protective layer it won't work. Though if you sand the surface, exposing the raw metal the beneath the coating, it'll often work then.To those having trouble with the pen: I promise you it really does work, just not on everything. To ensure a good marking experience you should gently sand the surface with ~250-500 grit sandpaper, and then clean it with isopropyl or another solvent. You need to get past the coatings, oils, and dirt on the surface to for the pen to work its oxidation magic.

Unfortunately it did not work well on 316L stainless steel tubes, which is what I needed it for. You could barely make the writing out on a non-machined surface. It did work well on almost everything else that I tried it on, however.

This product does have a short shelf life but it's not bad kind of faint on some metals

I’ve used this on 440c, 9cr18mov, D2, Cpm s45vn, 1095 so far and it works great on all of them. I’m assuming this marker has a ferric chloride solution in it. I haven’t had any issues but I would use caution when using it. With how quickly the acid marks on even high end stainless steels, it’s probably a pretty potent solution. Seems to be fairly low VOC but I’m sure you wouldn’t want to get this in your eyes, mouth, lungs, etc.

Delivered on today, September 30, with a Use by date of September.