Terms & Definitions

C2:

A glass-like coating that forms from Magnesuim Ortho Slilcate when grain-oriented material is mill-annealed. Adds greatly to interlaminar resistivity.

 

C3:

An organic coating also known as core plate that is applied to electrical steels to enhance interlaminar resistivity. C3 can actually add Lubricity to the surface of the material to enhance die life.

 

C4:

An inorganic coating applied to electrical steels to enhance interlaminar resistivity and, in the case of semi-processed materials, prevent the sticking, or fusing, of laminations in the final anneal of the lamination.

C5:

An inorganic coating (similar to, if not actually, C4) that contains ceramic fillers that enhance interlaminar resistivity. These ceramic fillers are typically quite abrasive and detrimental to die life.

 

Electrical Steel:

Any steel that is produced to be used in an application where specific magnetic properties are desired. These applications include Electric Motors, Transformers, Ballasts, Armatures, Stators, Rotors, Shunts, and other electrical product components.

 

Gauge:

The thickness of a material. There is little standardization of gauge numbers between different product types ie: 24-gauge Electrical Steel has a nominal thickness of .025", whereas in Cold-Rolled Commercial Quality steel, the nominal thickness of a 24-gauge product would be .024". Materials can be ordered to any decimal thickness, however, it is better to stay to standards as availability, price, and lead times increase when special gauges and tolerances are involved. See Electrical Steel and Commercial Quality Gauges charts.

 

Grain-Oriented:

Any electrical steel product in which, through the steelmaking process, the natural steel grains have been enlarged and oriented in the rolling direction to enhance the travel of the magnetic flux. Typical applications for Grain-Oriented materials are Transformers, Ballasts, and Magnetic Flux Shielding. Grain-Oriented materials are produced, typically, in two gauges .011" and .014" nominals.

 

Hardness:

Hardness refers as the name inplies to how hard a material is. Hardness is measured using a device that measures the amount of pressure required to physically deform the surface of the steel strip.

A hardness range is rarely specified for electrical steels where electrical characteristics are of primary concern, hardness is of a very secondary importance.

In the case of Commercial Quality Hot-Rolled and Cold-Rolled steels, hardness is a significant factor and is specified when ordered.

 

Hot-Rolled:

Any strip steel product that has been reduced only while the product was hot. Hot rolled products

 

Interlaminar Resistivity:

The resistance at the surface of the stacked lamination to flow of an electrical current through the lamination stack. Coatings are frequently applied to enhance the resistivity of electrical steels. See Electrical Steel Coatings:

 

Punching Quality (PQ):

A Grain-Oriented material that has had the production coating of C2 removed to allow for better die wear. Once the C2 coating has been stripped off C4 is typically applied. As of January, 1999 only one mill in the United States is known to produce Punching Quality Grain-Oriented material.

 

Shearing Quality (SQ):

Grain-Oriented typically has a very low sulpher content. This low content is acheived by applying a coating of Magnesium Ortho Slilicate to the surface of the steel strip before mill anneal. During the annealing process the MGoS leaches the sulpher out of the steel and at this high temperature forms a glass-like coating that is highly electrically resistive. This glass-like coating is called C2. While C2 is great for its electrically insulative properties it has a very detrimental effect on die wear. Grain-oriented materials which have had this coating removed are, hence, called Punching Quality. Frequently, M06 that contains the C2 coating is referred to as M07.

 

Strip Mill:

A facility that further reduces strip steel product to a specific gauge tolerance that is tighter than can be specified to a mill. Ie: To get a coil strip that is .025" +-.0005" one would send to a strip mill a coil that was .0255". The strip mill would then reduce said coil to .025" and guarantee the +-.0005" tolerance.