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Welding Glossary


 * Up Hand Weld ** - A vertical weld where the welder starts at the bottom and works upward


 * Underbead Crack ** . A crack in the heat-affected zone generally not extending to the surface of the base metal.


 * Undercut ** - A groove melted into the base metal adjacent to the toe or root of a weld and left unfilled by weld metal.


 * Underfill ** . A depression on the face of the weld or root surface extending below the surface of the adjacent base metal.


 * ULTRAVIOLET RADIATION - ** Ultraviolet radiation (UV) is generated by the electric arc in the welding process. Skin exposure to UV can result in severe burns, in many cases without prior warning. UV radiation can also damage the lens of the eye. Many arc welders are aware of the condition known as "arc-eye," a sensation of sand in the eyes. This condition is caused by excessive eye exposure to UV. Exposure to ultraviolet rays may also increase the skin effects of some industrial chemicals (coal tar and cresol compounds, for example).

**Upslope Time.** The time during which the welding current continuously increases from the beginning of welding current.

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