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What is a Swaging Machine?

Paul Scott
Paul Scott

A swaging machine is a device used to shape or change the dimensions of an item by forcing it into a die or a series of dies. These machines fall into two categories: tube or wire swaging or rotary swaging. Tube swaggers pull the item through a die to reduce its diameter while a rotary swagger features a series of dies used to hammer form the item. Swagged parts are typically cold worked although heat may be employed in some applications. Swaging machines may also be used to impart internal profiles in hollow parts.

Swaging is a commonly used industry process that can reduce the diameter of tubes, rods, and wire or change the form or shape of an item. These actions are achieved by employing two types of machines: tube and rotary swaging machines. The tube swaging machine is a diameter reducing device that functions by drawing a part, typically a cylindrical item such as a rod or tube, through a reducing die. Rotary swaging machines employ a number of shaped dies mounted within a cammed cage which open and close with considerable force on the part and effectively hammering it into shape. Smaller hydraulic swaging machine types are also used to secure termination and joint fittings onto steel ropes and electrical cables by deforming a ferrule or lug onto the cable or rope core.

A swagging machine can be used when making bullets from copper, lead or other materials.
A swagging machine can be used when making bullets from copper, lead or other materials.

Tube swaging operations typically begin with the tube, rod, or wire stock having its ends reduced in diameter or tagged on a rotary swaging machine. This reduced end profile simply facilitates easy insertion into a hardened steel swaging die of an appropriate diameter. Once the stock is fed through the die, it is attached to a draw bench trolley. The trolley is moved by means of a motorized chain drive and exerts considerable pressure on the stock, thereby pulling it through the die and reducing its diameter. When the draw bench mechanism has reached the end of its travel, the trolley is moved back to its starting position, reattached to the stock, and the process is repeated.

Rotary swaging is also used to reduce stock diameter but may also be utilized to swag or forge rounded or pointed ends onto an item. The bullet swagging machine is a good example of this forging action with solid brass, copper, or lead blanks being swagged or forged to the correct diameter and point profile. Rotary swaging machines typically employ a chuck which supports the stock centered in a group of two or four shaped swaging dies. The dies, in turn, are located within a cammed or lobed outer cage that rotates around the chuck and die axis. As it turns, it forces the dies up against the stock and then away again, sometimes up to 2,000 times per minute.

The constant hammering action of the dies then imparts the stock with the desired shape. Most tube and rotary swaging machine types are cold working machines although, in some specific cases, the parts may be heated prior to swaging. Internal profiles may also be swagged into hollow items with a swaging machine featuring a shaped mandrel which is forced into the hollow stock. This is commonly used to flare or bell the ends of steel and copper tubes for certain types of fittings.

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    • A swagging machine can be used when making bullets from copper, lead or other materials.
      By: vladimirfloyd
      A swagging machine can be used when making bullets from copper, lead or other materials.