Distance a fillet weld extends along each member, measured from the joint root to the toe on that side. An equal-leg 3/8 inch fillet has 3/8 inch legs and a theoretical throat of about 0.7 times that, roughly 0.265 inch. Legs are checked with fillet gauges, and long stretches of undersize leg are a common reject.
Heard on the job
Leg on that side is barely a quarter, print says five-sixteenths, add a pass.
Also heard as
- leg size
- leg length
- fillet size
Related terms
Fillet weld
Weld with a triangular profile laid in the corner where two members meet, the usual weld on T, lap and corner joints.
Throat
The thinnest section through a fillet weld, from the joint root to the face, which sets how much load it carries.
Toe
The edge of a weld bead, where weld metal blends into the surface of the base metal.