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.

I bought Fowler's chemical etching pen to darken metal hardware with unfinished surface. Here's one example where I used the marker to treat the surface of blot/nut on my keychain.As these bolt/nut combo is made of ferrous metal, I wanted to provide some corrosion resistance using the Fowler marker as well as darkening the surface finish to go with the black finish of the keychain.If you look at the 3rd photo, you can see the difference between unfinished surface (inside of the Phillips head) and the Fowler treated surface.So far I'm very happy with the outcome and durability.5 stars.

Won't mark some tools with clear coat unless you sand or grind it first.

Tried to etch my stainless steel range top but was not fine and not black... as shown in video of product.

Excellent poroduct

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.

I like these a lot. They are great for etching on metal. I took away one star because the tip gets mushy and they don't last very long. And they aren't cheap, so that's a bit of a disappointment. Otherwise, they work as advertised.