Welding rods are also known as filler metals or electrodes. It is basically a type of metal which is mostly used in the welding process to fill a joint that has to be fixed.

1. What are Welding Rods?
Welding rods are also
known as filler metals or
electrodes. It is basically a
type of metal which is
mostly used in the welding
process to fill a joint that
has to be fixed. The
process of welding is very
easy, a welding operator
has to melt the work pieces
and add a filler material,
often a welding rod, to
shape the molten material
which after cooling becomes
a strong joint.
Welding rods are available in four types. Covered welding rods are generally
used in metal arc welding. Welding rod coating consists of certain compounds
like rutile, calcium fluoride and cellulose, iron powder. Rutile-coated rods provide a
good appearance and good quality to the weld. Stainless steel rods are used to weld
steel work pieces.
Bare welding rods are basically used in gas metal arc welding or gas tungsten
arc welding. These rods contain metals like silicon, manganese, titanium and
aluminum which can prevent oxygen porosity. These rods have diameters ranging
from 0.7 mm to 2.4 mm.
Tubular welding rods are used in flux-cored arc welding. These rods contain
various metals such as stainless steel, high nickel etc. Welding fluxes are used in
submerged arc welding.
Source:
http://www.everlastgenerators.com/wordpress/welders/what-are-
welding-rods/