Which two weld types are known as "fillet" welds?

Fillet welds are characterized by their triangular cross-section and are typically used to join two pieces of metal at right angles to each other, or at other angles. The T-weld is a specific type of fillet weld formed when two metal pieces intersect, creating a "T" shape. It is most commonly used when welding joints formed by flat plates meeting at a perpendicular junction.

The lap weld, on the other hand, is made between two overlapping pieces of metal. It is also a type of fillet weld because it involves creating a weld along the edge of one piece against the surface of another.

Both T-welds and lap welds serve to provide strong connections in various structural applications, taking advantage of the fillet weld's ability to bind materials together effectively at different angles and junctions.