An air hammer is a pneumatic tool that uses pressurized air to drive a hammer head back and forth several thousand times a second. Air hammers come in a wide variety of sizes from handheld devices no bigger than a blow drier to five-foot-tall forging hammers for use in blacksmith shops and welding plants. Pneumatic jackhammers, such as those used to breakup concrete in streets, are also called air hammers. However the type being described in this article is that which could be used by a craftsman to shape, smooth, score, or cut a piece of metal. Air hammers allow these tasks to be carried out many times faster than would be possible with manual tools alone and often without the need to heat the object to be worked in a traditional forge.
Handheld air hammers are connected by tubes to an air compressor or to tanks that provide pressurized air. For simple shaping and smoothing jobs, especially involving soft metals like aluminum and copper, low pressures can be used. Stronger metals, such as stainless steel and heavy shaping jobs, demand higher pressures.
Most air hammers can be fitted with a variety of tips. These include hammer tips, for shaping and smoothing, and chisel tips, for scoring or cutting.
Before buying an air hammer, consider these important factors:
Special precautions must be taken when using air hammers because of the speed and pressures (several dozen pounds per square inch) at which they operate. Read the manufacturers instructions for details.
Plans for building air hammers, relatively inexpensively, simply, and easily, are available on the Internet.