Two pairs of drive rolls, mounted in tandem, are provided as the main mill power. Hydraulically loaded rolls are provided in order to prevent interruption of the cross-seam weld passing through the drive rolls and to contact the strip with as much friction surface as possible. Drive spindles are of heat-treated alloy steel, supported in sealed anti-friction bearings. Main mill drive gearboxes are totally enclosed with all gears running in an oil bath. Drive power is variable speed D.C. drive with remote speed control at the operator's console. Strip speed to be 10" (.4 m) to 100" (2.5 m) per minute.