In recent years, objects to be welded by resistance welding have been diversified and the load of
welding conditions is sometimes too much for a generally-used copper alloy electrode. There are some
cases that such load decreases the life of a welding electrode and makes the joining quality unstable.
Under specific severe welding conditions, W- and Mo-based materials have been used as electrode
materials with increasing frequency making the life of an electrode longer and improving the joining
quality.