TIG Torches and Consumables

What it is

A TIG (GTAW) torch carries current to a non-consumable tungsten electrode and delivers shielding gas around the arc. Torches are air-cooled or water-cooled, and are covered by IEC 60974-7. The front-end parts are:

• Collet: a split sleeve that grips the tungsten. Sized to the tungsten diameter.
• Collet body: screws into the torch head, holds the collet and directs gas.
• Gas lens: a collet body with fine screens that make the gas flow smooth. This allows longer tungsten stick-out and better coverage.
• Cup (nozzle): ceramic (alumina), heat-resistant glass or other materials. Shapes the gas.
• Back cap: seals the rear of the torch and holds the tungsten in place. Short, medium and long lengths.

How to identify

Torches are grouped in common series that share consumables, often known by numbers such as 9, 17, 20 and 26. The 9 and 17 families are smaller heads; the 20 is a water-cooled family; the 26 is a larger air-cooled family. Parts within a family interchange. Check the torch head marking or the maker's chart before ordering.

Cup sizes

Cup numbers show the inside orifice diameter in sixteenths of an inch.

Larger cups give wider gas coverage and need more gas flow. Gas lens cups are made to fit gas lens bodies and are not the same as standard cups.

Key points

• Collet, collet body and tungsten must all be the same diameter.
• Gas lenses help on stainless, titanium and joints where the tungsten must stick out farther.
• Pick tungsten type and diameter from the tungsten color code chart and the maker's current range.
• Water-cooled torches need coolant flow before the arc starts. Running without it destroys the torch.
• Torch current ratings depend on cooling, duty cycle and AC or DC use.

Common mistakes

• Using a collet that does not match the tungsten, which lets the tungsten slip.
• Mixing gas lens and standard cups.
• Using a short back cap with a long tungsten.
• Running a water-cooled torch with the cooler off.

Governing standards: IEC 60974-7 (torches); AWS A5.12 (tungsten electrodes); torch maker's parts chart. See the tungsten color code chart and shielding gas selection chart.

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.