I've been making my own stamps since I first went to work for a saddlemaker back in the 70's because that's what he did. I made my own leather knives, again as he did because the shape wasn't available commercially. If I can buy a stamp, I will. When what I want isn't available or if the lead time is too long, I will make my own. Some of them look fairly nice. Others are less than beautiful but the tip is what matters. Most have been made from old bolts because that's what was on hand when I needed to make one. I don't have many stainless ones but the steel doesn't make dark impressions when used. Just to be sure, I stamp a scrap a few times to clean the head before using it on a project. I've only had one tip corrode. That one got dipped in Birchwood Casey Super Blue to seal it after cleaning. I'm thinking of dipping all of my hand made ones to prevent that from happening in the future. Here's a pic of one of the more, shall we say, functional ones. As you can see, I didn't have to texture the barrel for ease of handling.