used in all positions, a "2" can be used only for flat and horizontal welds, and a "3" can
only be used for flat welds. The last number can range from "0" to "8"; it indicates the
type of covering on the electrode and the type of power supply that can be used.
All welding electrodes' should be stored in a clean, dry place. Many of the electrode
coatings have a special affinity for moisture and must have special protection if sound
welds are to be produced. Such rods should be stored in a heated oven and removed
only 30 to 45 minutes before use. A rod that has been exposed to moisture can be
dried out by following the manufacturer's recommendations.
Some of the electrode coatings contain fluoride compounds that can irritate the nose
and throat of the welder. Therefore, the welding area should be well ventilated, and
the welder should position himself so that he will not inhale the welding fumes.
Stainless steel electrodes or filler rods have the prefix "E" or "R" followed by a three-
digit number, with either a "15" or "16" at the end. The three-digit number indicates the
type of stainless steel. A "15" at the end indicates an electrode for use with dc current
only, and a "16" indicates an electrode for use with either ac or dc current. For
example, "E308-15" signifies an electrode that is 308 stainless steel used only with
Proper finish grinding of welded areas usually involves more time than the welding
itself. This time can be decreased considerably by obtaining a smooth weld with the
correct amount of fill material, selecting the correct grinding wheel, and using the
correct grinding wheel speed.
The following is an example of a grinding wheel marking, broken down for
51- A- 36- L- 5- V-23
51 - This is a prefix used by the manufacturer to indicate the type of
abrasive. Its use is optional.
A - This letter is used to indicate the type of abrasive. "A" stands for
aluminum oxide; "C" stands for silicon carbide.
36 - This number represents the grain size of the abrasive in the wheel.
These numbers range from 10 for coarse to 600 for very fine.