Jacob Morgan wrote:You could drop by a welding supply store or a hardware store and look at welding rods for TIG or oxy-fuel welding.
The weather was good enough to spend some time in the garage this weekend. Found a mostly-used pack of oxy-acet. welding rods that had been used to repair a lawn mower a few years ago. I think I also welded a few of the three foot lengths together to fish some wires through a wall full of insulation. It is mild steel, but stay with me.

Cut it to length with a chisel and a heavy vise, heated it up and forged it with a propane torch and a hammer, then used my 1" belt sander to smooth it up. I have a very old and very powerful bench grinder but for more precise work I prefer a 1" belt sander. I think it is easier to grind things flat, reduces or eliminates file work, runs cooler, is quieter, and it is easy to change grits.

It is mild steel, but I had a can of Kasenit, a case-hardening compound. Heat up the ends and the bends to cherry red and then dunk it into the powder. Repeat about four times. Each time more powder sticks to the metal. After it is good and coated heat it up to cherry red again. The coating bubbles and such and then quench in water. The case hardening turns the outer surface of the steel into high carbon steel and the rapid quench makes that outer surface hard. Even though the hardness is only on the outside that extra hardness probably makes it a little more resistant to bending. It was also out of 3/32" diameter steel, and even mild steel of that size is not going to bend that easily.

It worked but was ugly, so took some steel wool to it, cleaned it with acetone, then applied some cold blue. The instructions say to just apply it (to presumably room temperature metal), but I think it works ten times better if the metal is heated to a couple of hundred degrees (a quick pass through a propane torch) then applied. After the bluing is on it gets soaked in light oil or hosed down with WD-40. Cold blue does not give
that much protection against corrosion, but it helps and it looks better. What was in the photo was what I had on hand, I think this brand has to be mail ordered whereas other brands (esp. Brichwood Casey) may be available in the local sporting goods store. They all smell kind of bad and best to be doing this, and the case hardening, somewhere with good ventilation.

It had been made to fit the top of a keyway, as seen below. Have not noticed any issues with it bending or deforming. Besides the case hardening, it was fairly large in diameter to begin with. Made another wrench that has one end fitting the top of, and the other end the bottom of, a SC1 keyway. I have a Schlage cylinder that has spool pins and to go to the next level in picking I thought a really good wrench might make taking on security pins a little easier.

The welding rods were already on hand, but if one bought a pack they could make a whole lot of wrenches--27 feet for $6.59. The Kasenit was more than that, it has been a few years since I bought it and I don't recall what it cost. I think that brand may be off the market now. I had bought it from Brownells. Checked their on-line store just now and what they are selling currently is a store-brand for $20 a pound and a pound will go a long way.
http://www.brownells.com/GunTech/Brownells-Surface-Hardening-Compound/detail.htm?lid=14239 There is also another brand out there named Cherry Red. Might be easier to just buy some good steel to begin with, but if all one has is mild steel it can be made to work.