Swaging machines form a workpiece by forcing it into a die to reduce or increase the diameter of tubes or rods. Swaging is done by placing the tube or rod inside a die or dies that hammer together to reduce the diameter of the metal. Swaging machines do not result in the loss of material, only material deformation. Since there is no material loss, swaging machines are commonly used with precious metals. Swaging and swaging machines are commonly considered cold forming processes, but may also be done as a hot forming process in some situations.
Categories of Swaging Machines
Swaging machine processes are typically divided into two categories, tube swaging and rotary swaging. Tube swaging machines use a process similar to drawing wire. These swaging machines can be expanded by placing a mandrel in the tube and applying radial, compressive forces on the outer diameter, which allows the inside shape to differ from the outer, circular diameter.
Cold tube swaging machines are commonly used with aluminum, copper, and thin steel. Rotary swaging, also known as radial swaging, is often a cold working process used to reduce tube diameter, produce a tapered end, or to add a point to a round workpiece. This type of swaging machine uses two or four dies that hammer up to 2,000 a minute. Dies are mounted on the machine’s spindle, located inside a cage containing rollers, which is rotated by a motor. As the spindle spins inside the rotary swaging machine, the dies push out to ride the cage by centrifugal force. When the dies cross the rollers, they push the dies together due to their large size. Like tube swaging, rotary swaging can also create internal shapes inside the tube through use of a mandrel, as long as the shape has a constant cross-section.
Rotary swaging machines are common in two basic types, standard and butt swaging. Butt swaging machines contain sets of wedges that close the dies onto the workpiece by placing them between the annular rollers and the dies, often by use of a foot pedal. These swaging machines allow the piece to be inserted without the dies closing on it. Common applications for swaging machines include attaching fittings to cables or pipes, pipe flaring, sawmilling, fire arms and ammunition, rubber components, automotive components, aerospace applications, agricultural machinery, measurement and adjustment systems, medical devices, optics, tool construction, welding and brazing devices, jewelry manufacture, metal joining and fixtures, and more. Swaging machines may also be used for other, unlisted forming applications.