Stitch Weld Also known as intermittent weld. Stitch welding is not a continuous weld across a joint, but a weld broken up by space gaps in between welds, which results in a “stitch” look. It is not as robust and durable as a seam weld. It is used to prevent heat distortion and to also reduce the cost of welding if a long continuous weld is not necessary. There are two common types of stitch welds, fillet weld and butt joint weld. A fillet weld is a triangular seam weld that joins two surfaces at right angles to each other. Butt welds are generally in a lap joint, T-joint, or corner joint, which is most common amongst welding pipe or tubes to another surface where two pieces of metal are positioned coplanar and touching on one edge. Below are two photos of stitch fillet welds.