Abstract: An apparatus for overhead submerged arc welding having a pivotally mounted hopper containing flux and accommodating a bowl which has its open part facing towards a work being welded and communicating with a driven auger feeder for supplying and pressing the flux in the bowl and having a controlled drive. A welding nozzle extends through the bowl, and a former is provided above the brim of the open part of the bowl. A flux backing thickness pickup is connected to the controlled drive of the driven auger feeder for varying the number of revolutions of an auger of the driven auger feeder during a preset time period. The flux backing thickness pickup is mounted on a front edge of the bowl in the welding direction, adjacent to the longitudinal axis thereof, and is in the form of any eddy current transducer. By controlling the driven auger feeder, the apparatus monitors and keeps constant the preset flux backing thickness so as to supply a constant amount of flux to the bowl.