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.
Leicestershire (/ˈlɛstərʃər, -ʃɪər/ (About this soundlisten); postal abbreviation Leics.) is a landlocked county in the English Midlands, being within the East Midlands. The county borders Nottinghamshire to the north, Lincolnshire to the north-east, Rutland to the east, Northamptonshire to the south-east, Warwickshire to the south-west, Staffordshire to the west, and Derbyshire to the north-west. The border with most of Warwickshire is Watling Street, the modern A5 road.
Leicestershire takes its name from the city of Leicester located at its centre and administered separately from the rest of the county. The ceremonial county – the non-metropolitan county plus the city of Leicester – has a total population of just over 1 million (2016 estimate), more than half of which lives in the Leicester Urban Area.
Leicestershire remains the only county in England other than Greater London that has yet to adopt an official county flag.