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.
Kettering is a large market and industrial town in Northamptonshire, England, 70 miles (113 km) north of London and 15 miles (24 km) northeast of Northampton, west of the River Ise, a tributary of the River Nene. The name means "the place (or territory) of Ketter's people (or kinsfolk)".
At the 2011 census, it had a population of 93,475. The town is twinned with Lahnstein, in Germany and Kettering, Ohio, in the United States. It is part of the South Midlands and, along with other towns in Northamptonshire, has a growing commuter population as it is on the Midland Main Line railway, with East Midlands Railway services direct to London St Pancras International taking about an hour.