Features of the Completed Weld

Parent metal

Metal to be joined or surfaced by welding, braze welding or brazing.

Filler metal

Metal added during welding; braze welding, brazing or surfacing.

Weld metal

All metal melted during the making of a weld and retained in the weld.

Heat-affected zone (HAZ)

The part of the parent metal that is metallurgically affected by the heat of welding or thermal cutting, but not melted.

Fusion line

The boundary between the weld metal and the HAZ in a fusion weld, this is a non-standard term for weld junction.

Weld zone

The zone containing the weld metal and the HAZ

Weld face

The surface of a fusion weld exposed on the side from which the weld has been made.

Root

The zone on the side of the first run furthest from the welder

Toe

The boundary between a weld face and the parent metal or between runs, This is a very important feature of a weld since toes are points of high stress concentration and often they are initiation points for different types of cracks (e.g. fatigue cracks, and cold cracks). In order to reduce the stress concentration, toes must blend smoothly into the parent metal surface.

Excess weld metal

Weld metal lying outside the plane joining the toes. Other non-standard terms for this feature: Reinforcement, overfill.