782 Agricultural Mechanics and Technology Systems
Copyright Goodheart-Willcox Co., Inc.
The electrode lead carries current from the machine
to the electrode holder, an insulated clamp that holds the r
welding electrode. The electrode holder is sometimes
referred to as a stinger, Figure 29-7. A heavy-duty
connector engages a large surface area of the conductor
to attach the electrode holder to the welding cable. Most
common electrode holders are designed to accept the
electrode at multiple angles between two spring-loaded
contacts made from a copper alloy.
The workpiece lead is the lead from the work
to the machine. It is terminated with a workpiece
connector designed to make a firm electrical connection fi
to the workpiece. Commonly, this lead and clamp are
incorrectly referred to as the “ground.” It is not a direct
connection to ground. ANSI Z49.1, “Safety in Welding, Cutting and Allied
Processes,” states that the workpiece or the table that it rests on should be
connected to ground. Two common workpiece connector types are spring-
loaded models made from cast bronze alloy and those formed from light
sheet steel with alloy inserts used at contact points. See Figure 29-8.
Electrodes
Electrodes, or welding rods, are classifi by size and by type. The size fied
of an electrode is determined by its diameter measured at the wire core. Sizes
range from 1/16″ to over 3/8″ ″ in diameter. Electrodes with larger diameters ″
require more current and therefore produce more heat than smaller electrodes
of the same type. Electrode types are classifi according to the makeup of fied
their fl ux covering. fl
The insulating fl ux on the electrode protects the chemical integrity of the fl
weld. The heat of the arc causes parts of the fl ux to burn. The oxygen in the fl
immediate vicinity of the molten weld pool is used in the chemical reaction
of the burning, or oxidation, process. This creation of a gaseous shield leaves
little or no oxygen to bond with and contaminate the molten metal.
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Figure 29-7. Electrode holders.
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Figure 29-8. Different types of workpiece connections.
Safety Note
A A poor po or workpiece w or kp ie ce
connection n ec ti on can c an affect a ff ec t
weld we e ld d quality q q ua ua li li ty ty and a a nd nd create c c re re at at e e a a a
safety y hazard. An n effective ef fe ct iv e
connection of the power
suppl ly to the workpiece
ensures that th adequate
current t i is directed to the
weld and that a shock
hazard is not created by
stray current. Connection
devices should be regularly
checked to ensure that they
are in good condition.
Repair or replace damaged
or worn components.