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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 working.
The term swage may apply to the process (verb) or to a die or tool (noun) used in that process.
Swage is most often pronounced (AHD format: swāj).Headword "swage". The American Heritage Dictionary of the English Language, 4th ed. Houghton Mifflin, 2004, 2000.Headword "swage." Webster's Third New International Dictionary, Unabridged. Merriam-Webster, 2002. (Online version requires subscription to view.) http://unabridged.merriam-webster.com (Accessed 2007 March 10.) Another (less common) pronunciation sometimes heard in the metalworking industries is (AHD format: swĕj) (perhaps influenced by sledge as in sledgehammer).
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 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 the hole and are fed down into the part, deforming the metal in a controlled, predicted way. Grease is often used to lubricate this swaging process, which is also called roller swaging.
A swaging machine works by using two or four split dies which separate and close. This action is achieved by mounting the dies into the machine's spindle which is rotated by a motor. The spindle is mounted inside a cage containing rollers (looks like a roller bearing). The rollers are larger than the cage so as the spindle spins the dies are pushed out to ride on the cage by centrifugal force, as the dies cross over the rollers they push the dies together because of their larger size. On a four-die machine, the number of rollers cause all dies to close at a time; if the number of rollers do not cause all pairs of dies to close at the same time then the machine is called a rotary forging machine, even though it is still a swaging process.
A variation of the rotary swager is the creeping spindle swaging machine where both the spindle and cage revolve in opposite directions, this prevents the production of fins between the dies where the material being swaged grows up the gap between the dies.
There are two basic types of rotary swaging machine, the standard (also known as a tagging machine), and the butt swaging machine. A butt swaging machine works by having sets of wedges that close the dies onto the workpiece by inserting them between the annular rollers and the dies, normally by the use of a foot pedal. A butt swaging machine can allow a workpiece to be inserted without the dies closing on it, for example a workpiece can be inserted and then the dies closed, drawn through until remain and the dies are then released, the finished workpiece would then, for example, be but still of its initial diameter for at each end.
Pipe flaring machines are another example. Flared pieces of pipe are sometimes known as "swage nipples", "pipe swages", or "reducing nipples". In furniture, legs made from metal tubing (particularly in commercial furniture) are often swaged to improve strength where they come in contact with the ground, or casters.
In ammunition manufacture, swaged bullets are bullets manufactured by compressing metal at room temperature into a die to form it into the shape of a bullet. The other common manufacturing method is casting, which uses molten metals poured into a mold. Since metals expand when heated and contract when cooled, cast bullets must be cast with a mold slightly larger than the desired finish size, so that as the molten metal cools, it will harden at just the right point to shrink to the desired size. In contrast, swaged bullets, since they are formed at the temperature at which they will be used, can be formed in molds of the exact desired size. This means that swaged bullets are generally more precise than cast bullets. The swaging process also leads to fewer imperfections, since voids commonly found in casting would be pressed out in the swaging process. The swaging process in reference to cold flow of metals into bullets is the process not of squeezing the metals into smaller forms but rather pressing smaller thinner items to form into shorter and slightly wider shapes.
Individuals who make their own bullets usually are not aware of available manual specialized equipment and dies required for swaging bullets, and thus choose to make . To get high precision results, it is common to cast the bullets slightly oversized, then swage the resulting castings through a die to do the final forming. Since the amount of pressure required to size the bullet is far less than that required to form a bullet, a simple mechanical press can be used, often the same press used for handloading ammunition.
All of the larger manufacturers of reloading equipment have abandoned making or marketing bullet swaging equipment due to the downturn in the popularity of the manual methods and the subsequent loss of sales. Currently there are only a few die makers who manufacture and market bullet swaging equipment. Four die and equipment makers, CH/4D, RCE, Corbin, and Custom Maker Kaine Dies, manufacture the bulk of bullet swaging equipment in the United States.
In piano technology, swaging happens in several areas: key leads, underlever leads, and bass strings. Key leads which, in the piano's earliest history, were actually made using lead, are soft, round chunks that are inserted into holes drilled into the side of piano keys as a means of balancing actions. Key leads vary in size, generally small, medium, and large. Basically, key leads help to make a keyboard's touch light enough to play. Over time, fluctuations in humidity and aging of wood in piano key-sticks and underlevers causes space to develop around leads, causing them to rattle, tick, or knock. Loose leads in underlevers tend to be the most annoying to pianists because it's difficult to pinpoint where the noise (often a "tick" sound) is coming from. The remedy for the noise is swaging—squashing the leads with a short steel rod. Swaging the lead fills the void and eliminates the noise.
Bass strings in pianos are generally constructed with round—sometimes hexagonal—drawn-steel cores, over which copper is wound. Especially on round core wire, the last several inches of the area where the winding terminates is often flattened—swaged—to create a grabbing point for the copper winding material.
The term is now often used generically to refer to any similar designs.
As the force required for swaging increases during the process, the installation is finalised when the pintail breaks off. (1998). 9780824799779, Marcel Dekker. ISBN 9780824799779 Lockbolts could be viewed as a heavy-duty cousin of structural blind rivets ("pop rivets" in some regions), though the way the collar material's plastic deformation is achieved is different. Some tools are capable of "setting" both variants, as in both cases traction is applied to a sacrificial pintail.
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