guncotten is right on. Carbide is the way to go but be sure to clamp or vise what you're going to drill and use a drillpress. Most decent hardware stores have HHS bits with carbide tips for a fairly reasonable price. I use some solid carbide bits in thje gunsmithing business and they are expensive! I know, I use them for some gun applications, i.e., drilling for scope mounts on old Springfield rifles which have super hard receivers. I also about cry when I break one. BTW, the Springfield scope holes have to be tapped after drilling. The trick to do this is to sand a small area around the drilled hole nice and shiny so you can see a color change. Then belt sand, file, or turn down a short piece of aluminum rod/welding rod which you can tap firmly into the hole with an inch or so sticking out. You then heat the rod with a propane torch while being careful not to melt it. The hot aluminum rod will convey heat into the steel walls of the hole and the metal immediately around it. You watch the shined up area around the hole for a color change. When it turns blue/bluish, cut the torch and take out the rod. The hole area is now softened enough to be tapped---very carefully tapped. No reason why this wouldn't also work for knife steels so you could tap, enlarge a hole, or whatever. The gunsmith supply places and probably welder's supply stores also sell a product called "heat stop." This comes as a gray paste in a can. You can stick and form a dab of this, say silver dollar size and a half inch or so thick, atop a piece of hard steel and make a dime sized hole in the center of the dab. Then use a propane torch with a needle tip flame to heat that bare spot thus softening just that area for drilling. As the heat stop paste absorbs heat, it drys and turns brittle, and can then just be brushed off. A can of the stuff is just a few bucks and would last a knife maker for years. Hope this might be of luse. Regards
