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Models: WG3080, WG3090 and WG4130
Glossary of Welding Terms
AC or Alternating Current - electric current that reverses
direction periodically. Sixty cycle current travels in both
directions sixty times per second.
Arc Length - the distance from the end of the electrode to the
point where the arc makes contact with the work surface.
Base Metal - the material to be welded.
Butt Joint - a joint between two members aligned
approximately in the same plane.
Crater - a pool, or pocket, that is formed as the arc comes in
contact with the base metal.
DC or Direct Current - electric current which flows only in one
direction. The polarity (+ or -) determines which direction the
current is flowing.
DC Reverse Polarity - occurs when the electrode holder is
connected to the positive pole of the welding machine. Reverse
Polarity directs more heat into melting the electrode rather than
the work piece. It is used on thinner material.
DC Straight Polarity - occurs when the electrode holder is
connected to the negative pole of the welding machine. With
straight polarity more heat is directed to the work piece for
better penetration on thicker material.
Electrode - a coated metal wire having approximately the same
composition as the material being welded.
Fillet Weld - approximately a triangle in cross-section, joining
two surfaces at right angles to each other in a lap, T or corner
joint.
Flux - a coating, when heated, that produces a shielding gas
around the welding area. This gas protects the parent and filler
metals from impurities in the air.
Flux Cored Arc Welding (FCAW) - also called Gasless, is a
welding process used with a wire-feed welding machine. The
weld wire is tubular with flux material contained inside for
shielding.
Gas Metal Arc Welding (GMAW) - also called MIG, is a welding
process used with a wire feed welding machine. The wire is solid
and an inert gas is used for shielding.
Gas Tungsten Arc Welding (GTAW) - also called TIG, is a
welding process used with welding equipment with a high
frequency generator. The arc is created between a non-
consumable tungsten electrode and the work piece. Filler metal
may or may not be used.
Lap Joint - a joint between two overlapping members in parallel
planes.
Open Circuit voltage (OCv) - the voltage between the
electrode and the work clamp of the welding machine when
no current is flowing (not welding). The OCV determines how
quickly the arc is struck.
Overlap - occurs when the amperage is set too low. In this
instance, the molten metal falls from the electrode without
actually fusing into the base metal.
Porosity - gas pockets, or cavities, formed during weld
solidification. They weaken the weld.
Penetration - the depth into the work piece that has been heat
effected by the arc during the welding process. A good weld
achieves 100% penetration meaning that the entire thickness
of the work piece has been heated and resolidified. The heat
effected area should be easily seen on the opposite side of the
weld.
Shielded Metal Arc Welding (SMAW) - also called Stick, is a
welding process with uses a consumable electrode to support
the arc. Shielding is achieved by the melting of the flux coating
on the electrode.
Slag - a layer of flux soot that protects the weld from oxides and
other contaminants while the weld is solidifying (cooling). Slag
should be removed after weld has cooled.
Spatter - metal particles thrown from the weld which cool and
harden on the work surface. Spatter can be minimized by using
a spatter resistant spray on the work piece before welding.
Tack Weld - weld made to hold parts in proper alignment until
final welds are made.
Travel Angle - the angle of the electrode in the line of welding. It
varies from 5º to 45º depending on welding conditions.
T Joint - made by placing the edge of one piece of metal on the
surface of the other piece at approximately a 90º angle.
Undercut - a condition that results when welding amperage is
too high. The excessive amperage leaves a groove in the base
metal along both sides of the bead which reduces the strength
of the weld.
Weld Pool or Puddle - a volume of molten metal in a weld prior
to its solidification as weld metal.
Weld Bead - a narrow layer or layers of metal deposited on the
base metal as the electrode melts. Weld bead width is typically
twice the diameter of the electrode.
Work Angle - the angle of the electrode from horizontal,
measured at right angles to the line of welding.
