The inside diameter of a tube, pipe, or coil. It is the length of a straight line passing through the center of the opening. Specified in inches and fractions of an inch; or inches and decimals of an inch. Also called inner diameter.
ID scarfing
A manufacturing process used by tube and pipe producers to remove the internal longitudinal weld bead from the inside of the tube or pipe. See also scarfing.
idle pass
A section of vertical non-driven shafts, placed between the driven forming passes.
impact test
A destructive test used to measure the resistance of a metal to a sudden impact force.
inboard stand
The forming stand of a tube mill that is on the back or drive side of the mill.
inclusions
Particles of nonmetallic impurities, usually oxides, sulfides, or silicates, that are mechanically held in steel during solidification.
induction bending
A method or process of bending which employs an induction heating coil to create a narrow, circumferential, heated band around the material to be bent. When the appropriate temperature is reached, the material is pushed forward through the coil at a consistent speed and temperature while a bending moment is applied. After the material passes through the coil, it may be cooled (quenched) by forced air or water spray, or it may be allowed to cool naturally at ambient temperatures.
induction welding (IW)
A welding process that produces coalescence of metals by the heat obtained from the resistance of the workpieces to the flow of induced high-frequency welding current with or without the application of pressure. The effect of the high-frequency welding current is to concentrate the welding heat at the desired location.
ingot
A solid block of steel formed when molten steel is poured from a ladle into a mold, allowed to cool and solidify, and removed from the mold. Steel in this form is intended for subsequent rolling, forging, or extrusion.
inner diameter
The opening in the center of a tube, pipe, or coil. It is the length of a straight line passing through the center of the opening. Also called ID.
integral gearbox forming stand
A forming stand on a tube mill which is encased in one enclosure with the required drive gears.
intergranular corrosion
Corrosion which occurs preferentially along the grain boundaries of the alloy.
internal impeder
A nonconsumable component inserted inside a formed tube that keeps the majority of the heat energy applied by the work coil limited to the strip edges when welding a tube using the induction welding method.
intrados
The inside arc of the bend.
IPS
Internal pipe size.
ironing
A forming operation that involves the compression of metal under high pressure. This operation is used to increase the length of a tube or cup through reduction of wall thickness and outside diameter, the inner diameter remaining unchanged. This is the final forming process used to form beverage cans.
