Home/Technical Glossary/Seam Welding Seam Welding What is a seam weld? Seam welding is a variation of resistance spot welding. In resistance seam welding, however, the welding electrodes are motor driven wheels as opposed to stationary rods. The result is a ‘rolling’ resistance weld or non-hermetic seam weld. Resistance seam welding is used for joining two sheets of metal together: In laser seam welding, the part to be welded is moved or rotated under the laser focus head allowing laser spot welds to overlap. Key parameters for laser seam welding are the pulse repetition rate, measured in pulses per second (Hz) and the linear part travel rate or welding speed. Spot overlap percentage (a function of speed), pulse repetition rate and focused spot diameter are also used in the equation for determining the best laser for the job and for determining the total weld cycle time. Laser welding is used to make hermetic seam welds: Laser seam welding is used for applications including sensors, radar components, battery housing, conductors for thin film cells, pacemaker cases, and insulin pump cases.