| I.D. |
Inside diameter, the interior size of a pipe or tube, measured at its widest point. |
| Icicles |
An undesirable condition where excess weld metal protrudes beyond the root of the weld. |
| Ignition temperature |
The temperature at which a material will burn if enough oxygen is present. |
| Impact strength |
The ability of a material to withstand impact or hammering forces without cracking or breaking. |
| Impact test |
A test that carefully measures how materials behave under heavy loading, such as bending, tension, or torsion.Charpy or Izod tests, for example, measure energy absorbed when breaking a specimen. |
| Impurities |
Undesirable elements or compounds in a material. |
| Inch switch |
A switch on a welding machine that is used to slowly feed consumable wire through a combination cable to a TIG (GTAW) torch. |
| Incomplete fusion |
Failure of weld metal to fuse completely with the base metal or the preceding bead. |
| Inclusion |
A gas bubble or nonmetallic particle entrapped in the weld metal as a result of improper arc heat or filler material manipulation. |
| Inert gas |
A gas which does not normally combine chemically with the base metal or filler metal. |
| Indentation |
A depression left on the surface of base metal after a spot, seam, or projection weld is made. |
| Indenter |
In a hardness test, the ball or diamond that is pressed into the surface being tested. |
| Inductance |
In the presence of a varying current in a circuit, the magnetic field surrounding the conductor generates an electromagnetic force in the circuit itself.If a second circuit is adjacent to the first, the changing magnetic field will cause (induce) voltage in the second circuit.An application of this principle is the step-down transformer used in welding machines. |
| Infrared rays |
Heat rays which come from the welding arc. |
| Inert gases |
Shielding gases, such as argon, helium, that do not react with the weld. |
| Inorganic |
Being or composed of material that was never living; mineral, as compared to plant or animal. |
| Inorganic fluxes |
Welding fluxes that do not contain carbon.They are very corrosive, so they are not used on electrical or electronic parts. |
| Input power |
Electrical power required to operate a given welding machine. |
| Inside corner weld |
Two metals fused together; one metal is held 90 degrees to the other.The fusion is performed inside the vertex of the angle. |
| Inspection |
The process of examining welds for suitable, without damaging or destroying them. |
| Insulation |
A material that will not permit the flow of electricity, used as a covering on wires, cables, and electrode holders. |
| Intermittent weld |
Joining two pieces and leaving un-welded sections or gaps in the joint. |
| Interpass heating |
Heating or reheating a joint between the passes needed to complete the weld. |
| Inverter |
Power source which increases the frequency of the incoming primary power source. |
