For the third day, Bill was feeling a bit stretched out from a bunch of projects, and personal happenings. I had also worked 32 hours in the previous 3 days, so I was feeling beat myself. To quell our non-stop schedules, we took a trip to the Olympia Farrier Supply store to buy coal, check out hammers and chat with the salesman. It proved to be quite valuable as I learned a great deal about hammers. I did not know how to tell if a hammer is cast or forged. There are lots of articles out there describing the differences between cast vs forged metals. I'm sure you can find plenty of them for a more precise description (including this one).
Basically a casting involves liquid metal being poured into a form (made from all kinds of materials including, clay, sand, lost wax...) then the metal is cooled and the part you need is ready. It may involve some machining, for exact shape, but the majority of the work is done. Castings can be done at all different quality levels, but the major problems with castings are the grains of the metal can be pointed in different directions and voids can be present. Defects like cold shunts, porosity and inclusions can effect the strength of the metal.
Forging metal is what blacksmiths have traditionally done. This involved a coal forge, an anvil, a hammer and all the wonderful tools that smiths had the creativity to make. "In modern times, a gas-fired furnace, drop hammer and forging dies are used. The metal ingot is heated until it glows and placed in the drop hammer which pounds the ingot into the forging die. The result is the ingot takes the shape of the cavity machined into the forging die. The benefit of forging is that the metal grain flows around corners and makes a strong, uniform part." (From the forum linked above).
One way you can tell if something has been cast, is there is a line in the middle of the piece where the top of the casting mold and the bottom of the casting mold were smooshed together. Castings for hammers are typically made for the meat of the hammer head and a hard tool steel that is tempered is put on the face of the hammer. Cast hammers work very well, but are recognized as being somewhat inferior to forged hammers, due to the drawbacks of castings described above. This is not to say that they are not great hammers and Olympia Farrier Supply will replace any hammer that breaks if this unforeseen consequence was to happen. Forged hammers are recognized as superior which is reflected in their price.
While I learned so many things in our short session, it is difficult to re-cap all the things that were discussed. One other important hammer lesson that I learned was that the length of the hammer is based upon the length of your lower arm. In order to discover where the hammer should be held, you place the head in the crotch of your elbow and lay the handle down your forearm to your hand. Where the hammer handle hits your hand is where you would want to hold the hammer handle. Hammer handles are sold long so you can establish where you will hold it and then you can adapt the handle for the size you need. This seemed like common knowledge to Bill and the Farrier Supply salesman, but it was news to me and maybe you.
When we returned from our adventure out, we spent some time grinding steel rods for a class Bill was teaching that weekend and then hung out in Bill's studio and talked tools. Wow, education has a funny way of leading you to people and dropping you off on their front doorstep. I suggest you knock.