Swaging () is a forging process in which the dimensions of an item are altered using dies into which the item is forced. Swaging is usually a cold working process, but also may be hot worked. The term swage may apply to the process (verb) or to a die or tool (noun) used in that process. Origin The term "swage" comes from the Old French term souage, meaning "decorative groove" or "ornamental moulding". Swages were originally tools used by blacksmiths to form metal into various shapes too intricate to make with a hammer alone. These have handles for holding or pegs for attaching to an anvil, and often a flat head for striking with a hammer. Swage blocks are anvil-like dies with various shapes forged into them, which are also used for forming metal. Swages called "fullers" are specific to making grooves in swords and knives. Swage is most often pronounced (AHD format: swāj). Another (less common) pronunciation sometimes heard in the metalworking industries is (AHD format: swĕj) (perhaps influenced by sledge as in sledgehammer). Process As a general manufacturing process swaging may be broken up into two categories: The first category of swaging involves extrusion of the workpiece, forcing it through a confining die to reduce its diameter, similar to the process of drawing wire. This may also be referred to as "tube swaging". The second category involves two or more dies used to hammer a round workpiece into a smaller diameter. This process is usually called "rotary swaging" or "radial forging". Tubes may be tagged (reduced in diameter to enable the tube to be initially fed through the die to then be pulled from the other side) using a rotary swager, which allows them to be drawn on a draw bench. Swaging is normally the method of choice for precious metals since there is no loss of material in the process. Rotary swaging is usually a cold working process, used to reduce the diameter, produce a taper, or add a point to a round workpiece. It can also impart internal shapes in hollow workpieces through the use of a mandrel (the shape must have a constant cross-section). Swaging a bearing into a housing means either flaring its groove's lips onto the chamfer of the housing, or flaring the housing's material over the edge of the bearing. The flaring is done with a pair of rolls that travel around