Chapter 3: Welding Terms
root pass
1. An initial weld pass that provides complete penetration through the thickness of a joint member. 2. A weld pass made to produce a root bead.
electrode
A component of a welding circuit that conducts electrical current to a weld area.
crater
A depression at the termination of the weld bead.
fixture
A device used to maintain the correct positional relationship between weldment components as required by print specifications.
lamination
A discontinuity or defect that is aligned parallel to the working direction of a metal.
arc strike
A discontinuity resulting from an arc, consisting of any localized remelted metal, heat affected metal, or change in the surface profile of any metal object.
positioner
A mechanical device that supports and moves weldments for maximum loading, welding, and unloading efficiency.
base metal
A metal or alloy that is to be welded.
weld pass
A single progression of welding along a weld joint.
root bead
A weld bead that extends into or includes part or all of a joint root.
cold roll
A weld discontinuity that results in excessive weld on weld face; caused by incorrect personal speed (usually too fast) or machine settings; "muffin top" (as Liam said :-))
spatter
Droplets of molten metal or non-metallic material that are scattered or splashed during the welding process
weld toe
Junction of the base metal and the weld face
filler metal
Metal deposited in a welded, brazed, or soldered joint during the welding process.
slag inclusion
Non-metallic solid material entrapped in weld metal or between weld metal and base metal. Cause: not removing all slag or weld not cleaned out properly.
face reinforcement
Reinforcement on the same side as the welding.
root reinforcement
Reinforcement on the side opposite the one on which welding took place.
weld reinforcement
The amount of weld metal in excess of that required to fill the joint.
weld root
The area where filler metal intersects base metal and extends the furthest into the weld joint.
weld type
The cross-sectional shape of a weld.
root opening
The distance between joint members at the root of a weld before welding.
theoretical throat
The distance from the joint root, perpendicular to the hypotenuse of the largest right-angle triangle that can be inscribed within the cross section of a fillet weld.
weld width
The distance from toe to toe across the face of a weld.
depth of fusion
The distance that fusion extends into a base metal from the surface melted during welding.
weld face
The exposed surface of a weld, bounded by the weld toes on the side on which welding was done.
lack of fusion
The failure to melt into the surface or root edges of a joint; also called "lack of penetration" or "lack of drop-through"
effective throat
The minimum distance, minus convexity, between the weld face and the weld root.
root face
The portion of a groove face within a joint root.
slag
The residue or mass of metal left after smelting; worthless matter; the solidified remaining flux after the weld area cools.
ripple
The shape within the deposited bead caused by the movement of the welding heat source.
actual throat
The shortest distance from the face of a fillet weld to the weld root after welding.
faying surface
The surface of a joint member that is in contact with, or in close proximity to, the member to which it will be joined.
nugget
The weld metal that joins the members in spot, seam, and projection welds.
porosity
Weld metal contamination in the form of a trapped gas
overlap
When molten metal flows over the surface of the base material and then cools without fusing with the base material
undercut
When the edge of a weld has an inverse U shape
