Leg Length
The leg dimension is the length of the legs of a fillet weld from the theoretical intersection point to the respective run-out on the base material. It affects stress distribution and microstructure formation.
Physico-chemical mechanism of action
The leg size determines how the stresses are distributed during cooling. A longer leg size leads to slower cooling and can result in a finer microstructure.
Metallurgical relevance & risks during welding
A leg size that is too short can lead to high stresses and thus to cracks or hot cracks. A leg size that is too long can lead to a zone that cools too slowly, which can result in a finer microstructure and possibly a loss of toughness.
Workshop practice & instructions
For an optimal fillet weld, a leg size of 10 to 20 mm is recommended. This ensures adequate cooling and appropriate stress distribution, resulting in a safe and tough weld.