10
The gun must be extracted in perfect alignment with the bolt
to avoid deforming the clamp, and thus ensuring its long life-
span (phase 6).
5
WELDABILITY OF TYPICAL STUD BOLT/BASE
METAL COM BINATIONS FOR CAPACITOR
DISCHARGE WELDING.
(Table 1)
It is important to pay careful attention to the resistance and
deformity at the welding point between the stud bolt and
base metal. In the case of steel, you must pay particular
attention to brittleness.
The material and resistance of the stud bolt have limited tol-
erance; the carbon content in steel threaded stud bolts must
be < 0.20%.
The surface of the base metal must be clean. Layers of paint,
rust, waste, grease and non-weldable metal coatings must
be removed from the welding area. This must be done using
appropriate means. Base metals with layers of waste and
rust must be cleaned thoroughly.
6 WELDING
This technology makes it possible to weld threaded stud
bolts on clean, but not oxidized, surfaces of mild steel, gal-
vanized steel, stainless steel, aluminum and brass.
The rapidity of the process does not alter the surfaces on the
side opposite from the welding. Welding is not possible on
case-hardened steel, oxidized or painted metal.
Before beginning production it is essential to carry out a few
test welds to determine the proper setting of the power
source and gun (spring force), proceeding as follows:
· insert the chosen stud bolt in the clamp
X
(previously
adjusted as described in Fig. 2)
· arrange the base sheet metal in conditions identical to
those that will be used for the job in terms of thickness, earth
connection area, size of the workpiece, material quality.
· the terminals of the earth cable should be placed symmet-
rically, and as close as possible to the welding point.
· activate the power source by means of the lighted switch
I
.
· grip the gun and press it against the sheet metal, making
sure that its axis remains perpendicular to the surface. If the
surface of the material on which the stud bolt is to be weld-
ed is flat, we recommend mounting the three spacers Z after
first unscrewing the screws Y.
· carry out a few welds, adjusting the voltage using the keys
A
and
B
, and the force of the gun using the setting knob
Q
,
until the welding is perfect.
The gun should be removed keeping it perfectly aligned with
the bolt, to avoid deforming the clamp (Fig4).
6.1 WELDING ALUMINUM
To weld M4 threaded stud bolts in aluminum alloy Al Si 12
on sheet aluminum for auto body work, adjust the voltage to
105/115V. The gun spring that adjusts the pressure during
welding will be adjusted so that the index P is on 2/2.5.
7 MAINTENANCE
7.1 ROUTINE
Keep all instructions and figures on the welding machine
clear and legible.
The mains cable and welding cables must be insulated and
Fig. 4
Copper plated Stainless
Brass
Al. Mg 3
AISi 12
Al. 99,5
steel 0.2 C
steel
Cu Zn 38
Steel up to 0.30 C %
A
A
A
-
-
A
Galvanized steel
B
B
A
-
-
-
Stainless steel
A
A
B
-
-
-
Brass
A
B
A
-
-
-
Copper
B
-
A
-
-
-
Al 99,5
-
-
-
A
B
B
Al Mg 1
-
-
-
B
A
B
Al Mg 3 - Al Mg 5
-
-
-
B
A
B
Al Mg Si
-
-
-
B
A
B
High weldability: A
Low weldability: B
Not weldable: -
Tab.1
Base metal
Stud bolt metal
