Large Blacksmithing Machines

by Albin Drzewianowski

This month in the "Beginner's Corner" we have a vocabulary lesson. We are going to talk about power hammers, air hammers and stuff like that. As a beginner, it will probably be some time before you start using these tools, but if you hang around in blacksmithing circles, read blacksmithing newsletters and magazines, etc, you will see references to them. This lesson is to help give you a context so that you will understand what the others are talking about.

Power Hammers: This is probably the most talked about of the items to be discussed. The Power Hammer is a mechanical device to replace your arm. Generally they are the equivalent of a 25 pound hammer up to 250 pounds (and bigger) and strike at a speed of a couple hits per second. This tool is used for working bigger stock. You need to be careful, this tool can really hurt you if you don't know what you are doing.

Power Hammers can be divided into a number of categories: commercially made and home made; mechanical vs. air powered. The air powered come in two types: those supplied by a separate stand alone air compressor and those with a self-contained internal air compressor. Then there are the "junkyard hammers".

Commercially made mechanical hammers are epitomized by the Little Giant. Most of these were manufactured in the early to mid 1900's. I don't believe that there are any purely mechanical (by that I mean not air powered) power hammers currently being commercially manufactured. Powered by an electric motor, a shaft turns a flywheel which by way of a set of linkages causes the hammer head to go up and down. The hammer is controlled by a foot treadle. The unit has a large heavy cast iron frame. Generally, if you buy one of these hammers, you will need to do some amount of rebuilding on them simply due to their age. However, mechanically they are fairly simple. A "junkyard hammer" is a mechanical hammer, home-made from parts scrounged from the junkyard, or scrap yard. Sometimes using engine blocks for the anvil, rear differentials for the power linkages, these are examples of the creativity and ingenuity of the blacksmith. I get the impression, that they are more of a novelty item than a real working tool - a chance for the smith to show off his creativity and mechanical ability.

Air Hammers have replaced the mechanical hammer. Originally this type of hammer was powered by steam. Then they were converted to air power. They are available commercially from a number of suppliers. Also, many blacksmiths build their own. Until recently all of the home make air hammers required a separate air compressor. Plans for building one are available from AB ANA and on the internet. Generally you have an I-beam or a large heavy wall tube to support an air cylinder and hammer head. The trick to building one of these is to get the valving for the air cylinder right. The latest thing among the do-it-yourselfers, is to make an air hammer that has a self-contained air compressor. The high end commercial air hammers are of the self-contained style. With the self-contained hammers, you just plug them in. These self-contained hammers are considerably more expensive than the unit that requires a separate air compressor.

Treadle Hammers: This is a foot powered hammer which basically replaces the striker. It should not be thought of as a power hammer, rather it frees you up, so that you can hold the hot stock in one hand and a tool/chisel/punch in the other. Also, most treadle hammers are set up to use matching top and bottom tools. Picture a hardy hole in the anvil of the treadle hammer and a similar hole in the bottom of the hammer head, and these two line up perfectly. Generally the hammer head is in the range of 60 to 85 pounds. It is important to realize that the treadle hammer and the power hammer are really two different tools, although they have some overlap in function.

Hydraulic Presses: This tool is relatively new on the blacksmithing scene as compared to the other tools we have been talking about. Think of a log splitter mounted vertically and instead of splitting a log, it squeezes the metal. The hydraulic press is especially popular with knife makers and smiths who work really thick stock. A hydraulic cylinder allows you to exert tremendous pressure on to your hot steel. The drawback is that compared to power hammers, it is quite slow. (But remember, slower is also safer.) It really does not work well with small stock. The top and bottom dies pull too much heat from small stock. Many of these presses are set up to have two speeds, a fast speed when there is no load and a slower speed once it encounters load, i.e. your steel.

Fly Presses: This is a tool that goes way back in time. Also, it is much more popular in England and Europe. Picture a giant C-clamp with a fly wheel at the top mounted in a frame, or picture a cider press. The metal is worked by virtue of the power inherent in the very large screw thread. The flywheel is spun by hand rotating the screw and driving down the top die. A tremendous amount of power can be achieved by combining the stored energy of the flywheel and force transmission of the screw's thread. The advantages of this tool, is that it does not require electricity and allows great control. In other respects it is similar to the hydraulic press. If you are going to use one of these, you need to have the base anchored down very well. Using a fly press exerts tremendous rotational torque on the base.

Rolling Mills: This also is fairly recent, again, popular with knife makers. Picture the rolling mills used to make steel, but scaled down to a size that fits in a blacksmith shop. You have 2 rollers, one above the other and one or both is powered and you feed the hot steel through and it fullers the steel down to a thinner size (Think of a pie crust moving between a pair of rolling pins). These are commercially available, but many blacksmiths have made their own.

-- RebStaup - 25 Jan 2008