Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, is an arc welding process that uses a non-consumable tungsten electrode to produce the weld. The weld area and electrode are protected from oxidation or other atmospheric contamination by an inert shielding gas (argon or helium). A filler metal is normally used, though some welds, known as autogenous welds, or fusion welds do not require it. When helium is used, this is known as heliarc welding. A constant-current welding power supply produces electrical energy, which is conducted across the arc through a column of highly ionized gas and metal vapors known as a plasma. GTAW is most commonly used to weld thin sections of stainless steel and non-ferrous metals such as aluminum, magnesium, and copper alloys. The process grants the operator greater control over the weld than competing processes such as shielded metal arc welding and gas metal arc welding, allowing for stronger, higher quality welds. However, GTAW is comparatively more complex and difficult to master, and furthermore, it is significantly slower than most other welding techniques. A related process, plasma arc welding, uses a slightly different welding torch to create a more focused welding arc and as a result is often automated.
Kidderminster is a large market and historic minster town and civil parish in Worcestershire, England, 17 miles (27 km) south-west of Birmingham and 15 miles (24 km) north of Worcester. Located north of the River Stour and east of the River Severn, in the 2011 census, it had a population of 55,530. The town is twinned with Husum, Germany.
Situated in the far north of Worcestershire (and with its northern suburbs only 3 and 4 miles from the Staffordshire and Shropshire borders respectively), the town is the main administration centre for the wider Wyre Forest District, which includes the towns of Stourport-on-Severn and Bewdley, along with other outlying settlements.