Welding leads are available in a variety of diame-
ters. The diameter is referred to by number size. These
number sizes and their actual diameters are shown in
Figure 5-15. Figure 5-15 also shows what size lead
should be used to carry a given amperage to the weld-
ment and back. The amperages shown are the maxi-
mum that can be carried in the various leads over the
stated distances.
Lead Connections
Welding leads are connected to the welding
machine and base metal with lugs, clamps, or special
terminals. Figure 5-16 shows several lugs that may be
used on the machine end of the workpiece and elec-
trode leads. Lug connections can also be used to con-
nect the workpiece lead to the welding table. Special
push-and-turn connectors are shown in Figure 5-17.
These quick-connect terminals may be used on both
welding leads.
Various other types of clamps or special connec-
tors may be used to connect the workpiece lead to the
base metal. The workpiece lead may be clamped to
the base metal using a spring-loaded clamp, as shown
in Figure 5-18. Occasionally, a part must be welded
while it is being rotated. A special rotating workpiece
clamp is used for this application, Figure 5-19. Lugs,
spring clamps, or other special connectors are
mechanically connected or soldered to the bare end of
the leads.
Electrode Holder
The electrode holder is held by the welder during
the welding operation. The well-insulated handle of
the electrode holder protects the welder from electri-
cal shock. An electrode is clamped in the copper alloy
jaws of the electrode holder. The jaws provide a good
electrical contact for the electrode. See Figure 5-20.
The electrode lead is clamped into the electrode holder.
The cable clamp is under the insulated handle.
Protective Clothing
Pockets on shirts, pants, or coveralls should be
covered to prevent sparks from being caught in
them. The top collar button should be fastened,
especially when welding out of position. Pant legs
should not have cuffs.
A cap should be worn to protect your hair. Leather
gloves should be worn. Gauntlet gloves, leather gloves
with long cuffs,are the type preferred for out-of-position
welding. High-top shoes offer added safety from sparks.
Steel-toed shoes are recommended when working
around heavy metal parts.
Welding Technology Fundamentals 58
Welding Lead Current Capacities
Lead Number Lead Diameter Length Length Length
0 – 50 ft.
0 – 15.2 m
50 – 100 ft.
15.4 – 30.5 m
100 – 250 ft.
30.5 – 76.2 m
in. mm Amperage Amperage Amperage
4/0
3/0
2/0
1/0
1
2
3
4
.959
.827
.754
.720
.644
.604
.568
.531
24.4
21.0
19.2
18.3
16.4
15.3
14.4
13.5
600
500
400
300
250
200
150
125
600
400
350
300
200
195
150
100
400
300
300
200
175
150
100
75
Note: Lengths given are for the total combined length of the electrode and work leads.
Figure 5-15. Welding lead size recommendations. Lead sizes range from 4/0 to 4. If the work is 100′ (30.5 m) from the machine,
200′ (61 m) of leads are needed: 100′ (30.5 m) for the workpiece lead and 100′ (30.5 m) for the electrode lead. Size 1/0 leads are
required to carry 200A through 200′ (61 m) of leads.
Figure 5-16. These lugs are for arc welding leads. They are
usually connected to the lead by means of a mechanical crimp.
(Lenco)