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Gas Tungsten Arc Welding Handbook
move across the joint evenly. Movement of the torch
by the fi ngers alone usually results in incorrect torch
angles and a poor weld.
Torch angles are very important to maintain and
understand. The torch angles control the heat of the
arc, and the weld pool will move where it is directed
by the torch angles. Two different torch angles, the
work angle and the travel angle, greatly affect how the
weld bead is placed into the weld joint.
The work angle is the angle of the torch in a plane
that is perpendicular to the weld axis and is measured
from the perpendicular position to the torch’s actual
position. See Figure 8-6A. Work angles usually split
the weld pool evenly between the two pieces of base
metal. When the work angle points to one side of the
joint more than the other, the weld will move in that
direction. For example, on a fl at butt joint, the work
angle is 90°, straight up and down into the joint. Work
angles are generally straight into the middle of the
joint. The weld pool will show if the weld is favoring
one side or the other. When this happens, the welder
must adjust the work angle to correct the uneven weld.
The travel angle is the angle of the torch in the
plane parallel to the weld axis and is measured from
the perpendicular position to the torch’s actual posi-
tion. See Figure 8-6B. The torch should always be
pushed in the direction of the weld. Torch travel
angles are usually 15° to 20°. The main reason to main-
tain a good travel angle is so that the welder can see
the weld pool. The welder must be able to see the weld
pool when making any weld. The actual weld pool is
much smaller than the ceramic cup on the end of the
torch, so the torch must be laid over so the weld pool
can be seen. However, travel angles that are too severe
can suck air into the weld from the back side, causing
porosity or other discontinuities due to atmospheric
contamination.
For welding butt joints in any position, the
suggested work angle is generally 90°. Because the
work angle is perpendicular to the workpiece, it
provides maximum penetration. The suggested travel
angle for welding butt joints is typically a push angle
Figure 8-5.
Holding the torch in the manner shown
allows the welder to move the torch easily to change torch
angles. (Mark Prosser)
Work angle
Filler
rod angle
Travel angle
End View Side View
Figure 8-6.
Welders must be mindful of the travel angle, work angle, and fi ller rod angle. A—This end view of a fi llet weld
in progress shows how the work angle is measured. B—This side view of a fi llet weld in progress shows how travel angle
and fi ller rod angle are measured.