tommerr

Carbon monoxide will not migrate through the nickle phases.

Car springs make good bows. Yes, they are 6150 around 28Rc or so. Never use a broken spring! At this hardness, the spring can be heated to just blue and then bent. No aditional heat treating is necessary.

I work in an aerospace materials lab. I will look up times and temperatures for you. Any stress relieving or tempering must be done ASAP or stress cracking could occur. This is a good rule of thumb for all steels at .37% carbon or higher.

52100 is used for ball bearings.

Most taps are M2 tool steel. M2 has a very critical heat treatment. I do not recommend using them.

Estwing is here. They use 1045 steel for their hammers. One of our metalurgists called one of their's and somewhere I have their heat treating process. I don't trust Chinese products. Even their food kills people and dogs.

I analyze metals by x-ray fluoresence. That gives you everything but % carbon and sulfur. A full chemistrytakes a couple of hours. I must drill chips which get burned to produce carbon and sulfur dioxide. The instrument is basically a gas analyzer. Hardness testing is quick and simple but it leaves an indent. Therefore you supply a sample block which gets heat treated along with your work. The sample should be polished before hardening or the surface roughness can give a false "soft" reading.

I have a friend who never used safety glasses. Now he has a bad spot in the center of one eye.

I have worked in an aerospace materials laboratory for 35 years. I know a bunch of world class engineers. I do not forge, I form, I shape and I machine. I have been building guns for 40 years. I have done machining for 40 years. I have done firearms engraving for 35 years. So far that makes me 150 years old. I have access to lots of equipment to analyze steels and to heat treat them. I'm getting back into flintlocks. May I have your forming suggestions? I plan to form V springs. NEVER use a car spring that has broken in use. It's a bad piece of metal. Most flat springs are 6150 but some are 9255. There are spring benders locally. I will gladly buy their scraps rather than put many hours into an old piece of metal. That is not to say that most of the old springs out there are not just fine but they have been fatigued over a lot of miles. Every bump in the road is a stress.