TWI Frequently asked questions
by Steve Westgate
Resistance seam welding can be used to make gas- or fluid-tight joints in a variety of sheet metal fabrications. Steel fuel tanks for motor vehicles are a prime example. It is also used in making tin cans, steel drums and domesticradiators.
The process lends itself particularly to welding seams which are straight or have a regular curvature: abrupt changes in the weld line in any plane should be avoided. Welding is not possible into internal corners or where otherfeatures of a component obstruct access for the wheel electrodes.
Access to both sides of the joint is necessary, and a lap joint configuration is generally required. Components comprising two half shells may be welded, for example petrol tanks or domestic radiators. Alternatively, sheet can berolled into tubular form and the longitudinal seam welded, as in tin cans or steel drums.
