Steel Glossary

ASTM American Society for Testing Materials – it issues standards for line pipe products
A53A, A53B, A53F, A106 ASTM grades of carbon steel pipe
Bevel Angle formed between the prepared edge of the end of the tube and a plane perpendicular to the surface.  Standard line pipe bevel is 30 degrees.
Billet round, solid bar of steel which is pierced to form a seamless tube or pipe
Black pipe Denotes a lacquered outside diameter (OD) finish as opposed to bare or galvanized.
Carbide A compound of iron or other element and carbon in steel, forming a very hard, nonmetallic substance also called cementite.
Carbon steel Steel that has properties made up mostly of the element carbon and which relies on the carbon content for structure. Most of the steel produced in the world is carbon steel.
Cold drawn / rolling / sinking The process of pulling a tube through a carbide die to reduce the diameter of the tube. Small tubes with very high thickness-to-diameter ratios are commonly produced this way in long lengths. The sinking of the tube is done at room temperature (i.e.: “Cold”). This process usually produces closer tolerances and higher strength.
Chromium An alloying element that is the essential stainless steel raw material for conferring corrosion resistance. A film that naturally forms on the surface of stainless steel self-repairs in the presence of oxygen if the steel is damaged mechanically or chemically, and thus prevents corrosion from occurring.
Electrical Metal Tubing (EMT) Electrical metallic tubing, or EMT also nown as conduit. It is specially designed to protect the wiring contained within it. EMT is is made from high-grade rolled steel and the surface coated with zinc chromate. The coating helps prevent corrosion. EMT is easily cut and bent to fit most applications.
Hardfacing Abrasion-resistant metal applied by welding (usually in strips) on the surface of softer material to increase wear properties
Hardness Resistance to deformation or indentation. Materials with little resistance are called soft; and those with high resistance are called hard. Finer grained structures are harder than larger grained structures. The interest in hardness is because hardness correlates well with strength; with harder materials being stronger.
Heat A lot of steel produced by a furnace with one chemical composition. Steel melting is a batch process and each batch is a heat. Also known as a melt of steel. In austenitic stainless steels a heat is typically about 200,000 pounds of material, and will yield approximately 8 coils of 25,000 pounds each. Nickel base materials are typically melted in heats of 10,000 to 50,000 pounds, yielding 2 to 5 coils of 5,000 to 25,000 pounds each.
ID Inside diameter
LS Limited service – pipe not meeting specification, usually rejected at the mill
Nominal Pipe size or wall thickness as specified (not actual).  Sizes refer to approximate ID, even though OD is the fixed dimension.
OD Outside diameter
Quenching The process of rapidly cooling the steel from a temperature above the critical temperature.
Schedule Numbers assigned to different wall thicknesses of pipe (i.e. schedule. 40). The higher the number, the greater the thickness.
Seamless pipe/tubing Made by boring a hole through a steel bar and then rolling it, seamless pipe is stronger than welded pipe made by fusing together the steel plates and  rolling them into the form of pipe.
Stainless steel The broad classification of iron-based alloys (50% minimum iron) containing at least 10% chromium known for their excellent corrosion and heat resistance. Other elements are also added to form alloys for special purposes, in addition to the corrosion resistance imparted by chromium. Some of these elements are: nickel for increased corrosion resistance, ductility and workability; molybdenum for increased corrosion resistance, particularly resistance to pitting, increased creep strength and high temperature strength; columbium and titanium for stabilization; sulfur and selenium for improved machinability.
Tensile strength Rating of steel’s resistance to being pulled apart
XHY Extra heavy – pipe about 50% thicker than standard (ex.: sch. 80 for 1/8-8″)
Yield strength Tensile stress required to produce permanent elongation of a steel tube
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