Abbreviation for Society of Automotive Engineers. This organization has specified common and alloy steels and copper base alloys in accordance with a numerical index system allowing approximation of the composition of the metal. The last two digits always indicate the carbon content, usually within 0.05%.

Salt Spray Test
An accelerated corrosion test in which the metal specimens are exposed to a fine mist of salt water solution either continuously or intermittently.

Scab (Scabby)
A blemish caused on a casting by eruption of gas from the mold face or by uneven mold surface or occurring where the skin from a blowhole has partly burned away and is not welded.

The oxide of iron that forms on the surface of steel after heating.

Scaleless Blue
(See Black Oil Tempered Spring Steel)

(See Earing)

Machining the surface layers from ingots, billets and slabs before fabrication.

Scarf Joint
A butt joint in which the plane of the joint is inclined with respect to the main axes of the members.

Cutting surface areas of metal objects, ordinarily by using a gas torch. The operation permits surface defects to be cut from ingots, billets, or the edges of plate that is to be beveled for butt welding.

Scleroscope Hardness (Test)
A method for measuring the hardness of metals; a diamond-pointed hammer drops from a fixed distance through a tube onto the smoothed metal surface and the rebound measured. The scleroscope hardness value is empirically taken from the rebound distance, with specified high-carbon steel as 100.

Scrap (Ferrous)
Ferrous (iron-containing) material that generally is re-melted and recast into new steel. Integrated steel mills use scrap for up to 25% of their basic oxygen furnace charge; 100% of the mini-mills' raw material for their electric furnaces generally is scrap.

Home Scrap
Waste steel that is generated from within the steel mill, through edge trimming and rejects. It normally is sent directly back to the furnace.

Prompt Industrial Scrap
Excess steel that is trimmed by the auto and appliance stampers and auctioned to scrap buyers as factory bundles. This is a high-quality scrap as the result of its low-residual content and consistent chemistry.

Obsolete Scrap
Iron-bearing trash. Automobile hulks, worn-out refrigerators and useless storage tanks, for example, can be recovered from the junkyard and re-melted. The residual impurity of such scrap normally relegates obsolete scrap to the mini-mills ( No. 1 Heavy Melt).

Scrap Substitute
Raw material that can be charged in place of scrap in electric arc furnaces and basic oxygen furnaces. Scrap substitutes include, among others, DRI, HBI, iron carbide, and pig iron.

Scratch Brushed Finish
Finish obtained by mechanically brushing the surface with wire bristle brushes, by buffing with greaseless compound or by cold rolling with wire bristled rolls on scratch etched finish.

Seal weld
A weld, not being a strength weld, used to make a (sealing weld)

Sealing run
The final run deposited on the root side of a fusion (backing run)

Seam (defect)
On the surface of metal a crack that has been closed but not welded; usually produced by some defect either in casting or in working, such as blowholes that have become oxidized or folds and laps that have been formed during working. Similar to cold shut and laminations.

Seam Annealing
The process of heating the seam weld at a Pipe Mill to improve strength.

Seam Welding
An electric-resistance type of welding process, in which the lapped sheet is passed between electrodes of the roller type while a series of overlapping spot welds is made by the intermittent application of electric current.

Seamless Pipe
Pipe made from a solid billet, which is heated, then rotated under extreme pressure. This rotational pressure creates an opening in the center of the billet, which is then shaped by a mandrel to form pipe.

Secondary Hardening
Tempering certain alloy steels at certain temperatures so that the resulting hardness is greater than that obtained by tempering the same steel at some lower temperature for the same time.

Secondary Metal
Scrap metal that has been recycled.

Secondary Steel
Steel that does not meet the original customer's specifications because of a defect in its chemistry, gauge or surface quality. Mills must search to find another customer (that can accept the lower quality) to take the off-spec steel at a discount. While secondary will not affect the reported yield, margins will suffer.

The designation given to sheet or strip that has imperfections in moderate degree or extent, which may be classified in two general groups -- imperfections in the base material, or other manufacturing defects. This term not used in connection with non-ferrous alloys.

Segment Steel
Used for laminated piston rings. Carbon content about .60%. Hardened and blue tempered with round edges. Hardness usually Rockwell 30 N 68 to 71, widths vary from .058 to .163 and thicknesses are .020, .024 and .030.

Non-uniform distribution of alloying elements, impurities or phases.
In an alloy, concentration of alloying elements at specific regions, usually as a result of the primary crystallization of one phase with the subsequent concentration of other elements in the remaining liquid.

Segregation Banding
In homogeneous distribution of alloying elements aligned on filaments or plates parallel to the direction of working.

Self Diffusion
The spontaneous movement of an atom to a new site in a crystal of its own species.

Self-Hardening Steel
A steel containing sufficient carbon or alloying element, or both, of form martensite either through air hardening or, as in welding and induction hardening, through rapid removal of heat from a locally heated portion by conduction into the surrounding cold metal.

Semi-finished Steel
Steel shapes—for example, blooms, billets or slabs—that later are rolled into finished products such as beams, bars or sheet.

Semi-fabricated products.

Sendzimir Mill

  • WHAT
    A mill having two work rolls of 1 to 2 1/2-in diameter. each, backed up by two rolls twice that diameter and each of these backed up by bearings on a shaft mounted eccentrically so that rotating it increases the pressure between bearings and backup rolls.
  • WHY
    To control the thickness of steel better at lower capital cost, and to roll thinner sheets and strips.
  • HOW
    Stainless steel sheet or strip passes between a matching pair of small work rolls with extremely smooth surfaces, heavily reinforced by clusters of back-up rolls. The rolls reduce the steel to the desired thickness. Service Center A catchall name for an operation that buys steel, often processes it in some way and then sells it in a slightly different form. A service center is distinguished from an end-user by the fact that, unlike an end-user, a service center sells steel, not a fabricated product. Service centers are manufacturers to the extent that they add labor to steel by providing a service.

Semikilled Steel
Steel that is incompletely deoxidized and contains sufficient dissolved oxygen to react with the carbon to form carbon monoxide and thus offset solidification shrinkage.

Cast iron (not steel) of high quality, obtained by using a large percentage of steel scrap with the pig iron.

Settlement Price
The official cash sellers price (offer) announced each day by the LME, which the London Clearing House uses to settle contracts.

Shape Correcting
Rolling, heating and quenching steel sheets often affect the dimensions of the steel. Levelers, temper mills and edge trimmers rework the processed steel to match customer specifications.

Shear Bands (deformation)
Bands in which deformation has been concentrated in homogeneously in sheets that extend across regional groups of grains. Usually only one system is present in each regional group of grains, different systems being present in adjoining groups. The bands are non-crystallographic and form on planes of maximum shear stress (55(degrees) to the compression direction). They carry most of the deformation at large strains. Compare microbands.

A type of cutting operation in which the metal object is cut by means of a moving blade and fixed edge or by a pair of moving blades that may be either flat or curved.

Shear Crack
A diagonal, transgranular crack caused by shear stresses.

Shear Steel
Steel produced by forge welding together several bars of blister steel, providing a more homogeneous product.

Shear Strength
The stress required to produce fracture in the plane of cross section, the conditions of loading being such that the directions of force and of resistance are parallel and opposite although their paths are offset a specified minimum amount.

If the edges of sheet and strip are not controlled during reduction, they must be trimmed parallel by shears. This process may be performed by either the steel mill or steel processor to match customer needs.

Sheet Steel
Thin, flat-rolled steel. Coiled sheet steel accounts for nearly one-half of all steel shipped domestically and is created in a hot-strip mill by rolling a cast slab flat while maintaining the side dimensions. The malleable steel lengthens to several hundred feet as it is squeezed by the rolling mill. The most common differences among steel bars, strip, plate, and sheet are merely their physical dimensions of width and gauge (thickness).

Product Classification by Size

Specified Thickness
In Inches

Specified Width in Inches

Up to 6

Over 6 to 8

Over 8 to 12

Over 12 to 48

Over 48

0.2300 +






0.2299 - 0.2040






0/2039 - 0.1800






0.1799 - 0.0449






Source: Smith Barney Inc./Salomon Brothers Inc.

Shell Molding
Forming a mold from thermosetting resin-bonded sand mixtures brought in contact with preheated (300 to 500 (degrees) F) metal patterns, resulting in a firm shell with a cavity corresponding to the outline of the pattern. Also called Croning process.

Shielded-Arc Welding
Arc welding in which the arc and the weld metal are protected by a gaseous atmosphere, the products of decomposition of the electrode covering, or a blanket of fusible flux.

A thin flat hard metal strip produced to close tolerances; used primarily for tool, die and machine alignment purposes. In steel there are four general types: (1) Low Carbon Rockwell B 80/100; (2) Hard Rolled High Carbon Rockwell C 28/33. (3) Hardened and Tempered Spring Steel Rockwell C 44/51; (4) Austenitic Stainless Steel Rockwell C 35/45. Brass shim of commercial quality is also used and most generally specified is 2 Nos. Hard but may be 4 Nos. Hard.

Shore Hardness (Test)
(See Scleroscope Hardness)

An open position for the sale of metal.


Short Terne
A term applying to terne coated (Lead and Tin) sheets with reference to Base Box sizes (14 x 20) Refer to terne plate.

A form of brittleness in metal. It is designated as cold, hot, and red, to indicate the temperature range in which the brittleness occurs.

Shot Blasting
Cleaning surface of metal by air blast, using metal as a result of solidification shrinkage and the progressive freezing of metal towards the center.

Shot peening
Stressing the surface layer of a material by bombarding it with a selected medium (usually round steel shot) under controlled conditions.

Shredded Scrap
Fist-sized, homogenous pieces of old automobile hulks. After cars are sent through a shredder, the recyclable steel is separated by magnets. Mini-mills consume shredded scrap in their electric arc furnace operations.

Shrinkage Cavity
A void left in cast metals as a result of solidification shrinkage and the progressive freezing of metal towards the center.

Shrinkage groove
A shallow groove caused by contraction of the metal along each side of a penetration bead.

Side bend test
A bend test in which the face of a transverse section of the weld is in tension

Side Trimming
This is when the sides of the strip are continually being sheared off while the strip is being pulled into two vertical overlapping knives.

Sigma Phase
An extremely brittle Fe-Cr phase that can form at elevated temperatures in Fe-Cr-Ni and Ni-Cr-Fe alloys.

Silicon (Si)
(Chemical symbol Si) Element No. 14 of the periodic system; atomic weight 28.06. Extremely common element, the major component of all rocks and sands; its chemical reactions, however, are those of a metalloid. Used in metallurgy as a deoxidizing scavenger. Silicon is present, to some extent, in all steels, and is deliberately added to the extent of approximately 4% for electric sheets, extensively used in alternating current magnetic circuits. Silicon cannot be electrodeposited.

Silicon Electrical Steel
A type of specialty steel created by introducing silicon during the steelmaking process. Electrical steel exhibits certain magnetic properties, which make it optimum for use in transformers, power generators and electric motors.

  • Grain-Oriented
    The metal's grain runs parallel within the steel, permitting easy magnetization along the length of the steel. Although grain-oriented steel may be twice as expensive to produce, its magnetic directional characteristics enable power transformers, made from this metal, to absorb less energy during operation.
  • Non-Grain-Oriented
    Because there is no preferential direction for magnetization, non-grain-oriented steel is best used in rotating apparatus such as electric motors.

Diffusing silicon into solid metal, usually steel, at an elevated temperature.

Silky Fracture
A steel fracture that has a very smooth fine grain or silky appearance.

Silver Solders
Alloys of silver, copper, zinc and other metals, melting between 650 and 875 (degrees) C. used for making strong yet moderately ductile joints that resist corrosion.

Single-Action Press
A forming press that operates with a single function, such as moving a punch into a die with no simultaneous action for holding down the bland or ejecting the formed work.

Sinker Steel
Used for making sinkers in hosiery making machinery. Supplied both hardened and tempered and cold rolled and annealed. Usually extra precision rolled and extra flat. Carbon content about 1.25.

A reservoir insulated to retain heat and to hold excess molten metal on top of an ingot mold, in order to feed the shrinkage of the ingot. Also called shrink head or feeder head. (See Hot Top)

Sintered Carbide
Composite, containing carbides of extremely refractory metals, such as tungsten, tantalum, titanium, etc., cemented together by a relatively low-melting metal, such as cobalt acing as a matrix.

Converting powder into a continuous mass by heating to a temperature considerably below fusion, usually after preliminary compacting by pressure.
It is a process that combines iron-bearing particles, once recovered from environmental control filters, into small pellets. Previously, these materials were too fine to withstand the air currents of the smelting process and were thrown away. The iron is now conserved because the chunks can be charged into the blast furnace (see Agglomerating Processes).

Steel that is the entry material to a pipe mill. It resembles hot-rolled strip, but its properties allow for the severe forming and welding operations required for pipe production.

A thin surface layer that is different from the main mass of a metal object, in composition, structure or other characteristics.

Skin Pass Rolling
A light cold rolling operation that is employed to improve flatness, produce the final surface finish or texture, develop mechanical properties, and/or reduce the tendency of stretcher strain or fluting during forming.

Skip sequence
A welding sequence in which short lengths of run are (skip welding )

A layer of solidified metal or dross on the wall of a pouring vessel often when metal has been poured.

The most common type of semi-finished steel. Traditional slabs measure 10 inches thick and 30-85 inches wide (and average about 20 feet long), while the output of the recently developed "thin slab" casters is approximately two inches thick. Subsequent to casting, slabs are sent to the hot-strip mill to be rolled into coiled sheet and plate products.

Slack Quenching
The process of hardening steel by quenching from the austenitizing temperature at a rate slower than the critical cooling rate for the particular steel, resulting in incomplete hardening and the formation of one or more transformation products in addition to or instead of martensite.

The impurities in a molten pool of iron. Flux such as limestone may be added to foster the congregation of undesired elements into a slag. Because slag is lighter than iron, it will float on top of the pool, where it can be skimmed.

A configuration in a joint or joint preparation which may lead to the entrapment of slag.

Plastic deformation by irreversible shear displacement of one part of a crystal relative to another in a definite crystallographic direction and on a definite crystallographic plane.

Slip Direction
The crystallographic direction in which translation of slip takes place.

Slip Line
Trace of a slip plane on a viewing surface.

Slip Plane
The crystallographic plane on which slip occurs in a crystal.

When two or more widths are obtained from the hot rolled substrate width.  The slitting operation results in a cut edge.

Slit Edges
The edges of sheet or strip metal resulting from cutting to width by rotary slitters.

A processing unit that is used for side trimming or slitting into multiples.

Cutting a sheet of steel into narrower strips to match customer needs. Because steel mills have limited flexibility as to the widths of the sheet that they produce, service centers normally will cut the sheet for the customer.

Sliver (defect)
Loose metal piece rolled down onto the surface of the metal during the rolling operations.

Slot lap joint
A joint between two overlapping components made by depositing a fillet weld round the periphery of a hole in one component so as to join it to the other component exposed through the hole.

A processor of mine feed or scrap material (secondary smelter) which produces crude metal.

Prolonged heating of a metal at selected temperature.

Soft Skin Rolled Temper (No. 4 Temper)
In low carbon-rolled strip steel, soft and ductile. Produced by subjecting annealed strip to a pinch pass or skin rolling (a very light rolling).

Solder Embrittlement
Reduction in ductility of a metal or alloy, associated with local penetration by molten solder along grain boundaries.

Joining metals by fusion of alloys that have relatively low melting points -- most commonly, lead-base or tin-base alloys, which are the soft solders. Hard solders are alloys that have silver, copper, or nickel bases and use of these alloys with melting points higher than 800 (degrees) F. is generally termed brazing.

Solid Solution
A solid crystalline phase containing two or more chemical species in concentrations that may vary between limits imposed by phase equilibrium.

In a constitutional diagram, the locus of points representing the temperatures at which various components finish freezing on cooling or begin to melt on heating.

The component of either a liquid or solid solution that is present to the lesser or minor extent; the component that is dissolved in the solvent.

Solution Heat Treatment
A heat treatment in which an alloy is heated to a suitable temperature, held at that temperature long enough to cause one or more constituents to enter into solid solution, and then cooled rapidly enough to hold these constituents in solution.

Solution Heat Treatment
Heating an alloy to a suitable temperature, holding at that temperature long enough to allow one or more constituents to enter into solid solution, and then cooling rapidly enough to hold the constituents in solution. The alloy is left in a supersaturated, unstable state, and may subsequently exhibit quench aging.

The component of either a liquid or solid solution that is present to the greater or major extent; the component that dissolves the solute.

In a phase or equilibrium diagram, the locus of points representing the temperature at which solid phases with various compositions coexist with other solid phases; that is, the limits of solid solubility.

Structure of steel, resulting from the tempering of martensite. In a truly sorbitic structure, the cementite is completely dispersed in the matrix. The trend is to call this structure tempered martensite.
It is a fine mixture of ferrite and cementite produced either by regulating the rate of cooling of steel or tempering steel after hardening. The first type is very fine pearlite difficult to resolve under the microscope; the second type is tempered martensite.

Sorbitic Pearlite
Structure of steel resulting, on cooling under the proper conditions, from the decomposition of austenite; has a fine, lamellar appearance.

Space Lattice (crystal)
A system of equivalent points formed by the intersections of three sets of planes parallel to pairs of principal axes; the space lattice may be thought of as formed by the corners of the unit cells.

Space-Centered (concerning space lattices)

The cracking and flaking of particles out of a surface.
The spangle of a hot-dip coated sheet surface is the visual manifestation of the grains that form within the coating when it solidifies as the sheet emerges from the pot of molten coating metal. The spangle or grain varies in size, brightness and surface relief, depending upon a number of factors, most of which are related to the composition of the coating and cooling practices.

Special Bar Quality (SBQ)
SBQ represents a wide variety of higher-quality carbon and alloy bars that are used in the forging, machining and cold-drawing industries for the production of automotive parts, hand tools, electric motor shafts and valves. SBQ generally contains more alloys than merchant quality and commodity grades of steel bars, and is produced with more precise dimensions and chemistry.

Specialty Steel
Category of steel that includes electrical (see Silicon Electrical Steel), alloy (see Alloy Steel), stainless (see Stainless Steel) and tool (see Tool Steels) steels.

Specialty Tube
Refers to a wide variety of high-quality custom-made tubular products requiring critical tolerances, precise dimensional control and special metallurgical properties. Specialty tubing is used in the manufacture of automotive, construction and agricultural equipment, and in industrial applications such as hydraulic cylinders, machine parts and printing rollers. Because of the range of industrial applications, the market typically follows general economic conditions.

Specific Gravity
A numerical value representing the weight of a given substance as compared with the weight of an equal volume of water, for which the specific gravity is taken as 1.0000.

An optical instrument for determining the presence or concentration of minor metallic constituents in a material by indicating the presence and intensity of specific wave lengths of radiation when the material is thermally or electrically excited.

Spelter (Prime Western Spelter)
A low-grade of Virgin Zinc containing approximately 98% Zinc used in Galvanizing processes.

Heating and cooling to produce a spherical or globular form of carbide in steel.
Spherodizing methods frequently used are:
1. Prolonged holding at a temperature just below Ae1. .
2. Heating and cooling alternately between temperatures that are just below Ae1. .
3. Heating to temperature above Ae1 or Ae3 and then cooling very slowly in the furnace or holding at a temperature just below Ae1. .
4. Cooling at a suitable rate from the minimum temperature at which all carbide is dissolved, to prevent the reformation of a carbide network, and then re-heating in accordance with methods 1 or 2 above. (Applicable to hypereutectoid steel containing a carbide network.

Spherodizing Annealing
A subcritical annealing treatment intended to produce spherodization of cementite or other carbide phases.

Spherodized Structure
A microstructure consisting of a matrix containing spheroidal particles of another constituent.

High-manganese pig iron, containing 15-30% manganese, approximately 5% carbon, and less than 1% silicon used in the manufacture of steel by the Bessemer, or basic open-hearth process.

The procedure of making sheet metal discs into hollow shapes by pressing the metal against a rotating form (spinning chuck) by a tool.

Spot Market
Sales for delivery in less than three months.

Spot Welding
Welding of lapped parts in which fusion is confined to a relatively small circular area. It is generally resistance welding, but may also be gas-shielded tungsten-arc, gas-shielded metal-arc, or submerged-arc welding.
It is an electric-resistance welding process in which the fusion is limited to a small area. The pieces being welded are pressed together between a pair of water-cooled electrodes through which an electrical current is passed during a very short interval so that fusion occurs over a small area at the interface between the pieces.

Spray transfer

Metal transfer which takes place as globules of diameter substantially larger than that of the consumable electrode from which they are transferred.

b A term referring to the difference in two prices. The contango or backwardation between two prompt dates or the difference between the bid and offer price.

Spring Steel
Steel, normally of the high-carbon or alloy type, used in the manufacture of springs, lending itself to appropriate heat treatment; usually made is the open hearth or electric furnace.

Spring Steel Strip
Any of a number of strip steels produced for use in the manufacture of steel springs or where high tensile properties are required marketed in the annealed state, hard rolled or as hardened and tempered strip.

Spring Temper
In brass mill terminology, Spring Temper is eight numbers hard or 60.50% reduction.

An indicator of elastic stresses, frequently measured as the increase in diameter of a curved strip after removing it from the mandrel about which it was held. The measurement is employed as an indicator of the extent of recovery or relief of residual stresses that has been achieved by the transformation of elastic strain to plastic strain during heating or stress relieving.

Stabilizing Annealing
A treatment applied to austenitic stainless steels that contain titanium or columbium. This treatment consists of heating to a temperature below that of a full anneal in order to precipitate the maximum amount of carbon at titanium carbide or columbium carbide. This eliminates precipitation at lower temperatures, which might reduce the resistance of the steel to corrosion.

Stabilizing Treatment
Any treatment intended to stabilize the structure of an alloy of the dimensions of a part.
(1) Heating austenitic stainless steels that contain titanium, columbium, or tantalum to a suitable temperature below that of a full anneal in order to inactivate the maximum amount of carbon by precipitation as a carbide of titanium, columbium, or tantalum.
(2) Transforming retained austenite in parts made from tool steel.
(3) Precipitating a constituent from a nonferrous solid solution to improve the workability, to decrease the tendency of certain alloys to age harden at room temperature, or to obtain dimensional stability.

Stack cutting
The thermal cutting of a stack of plates usually clamped together.

Staggered intermittent weld
An intermittent weld on each side of a joint (usually fillet welds in T and lap joints) arranged so that the welds on one side lie opposite the spaces on the another side along the joint.

Stain Finish
(See Scratch Brushed Finish)

Stainless Steel
The term for grades of steel that contain more than 10% chromium, with or without other alloying elements. Stainless steel resists corrosion, maintains its strength at high temperatures, and is easily maintained. For these reasons, it is used widely in items such as automotive and food processing products, as well as medical and health equipment. The most common grades of stainless steel are:

  • TYPE 304
    The most commonly specified austenitic (chromium-nickel stainless class) stainless steel, accounting for more than half of the stainless steel produced in the world. This grade withstands ordinary corrosion in architecture, is durable in typical food processing environments, and resists most chemicals. Type 304 is available in virtually all product forms and finishes.
  • TYPE 316
    Austenitic (chromium-nickel stainless class) stainless steel containing 2%-3% molybdenum (whereas 304 has none). The inclusion of molybdenum gives 316 greater resistance to various forms of deterioration.
  • TYPE 409
    Ferritic (plain chromium stainless category) stainless steel suitable for high temperatures. This grade has the lowest chromium content of all stainless steels and thus is the least expensive.
  • TYPE 410
    The most widely used martensitic (plain chromium stainless class with exceptional strength) stainless steel, featuring the high level of strength conferred by the martensitic. It is a low-cost, heat-treatable grade suitable for non-severe corrosion applications.
  • TYPE 430
    The most widely used ferritic (plain chromium stainless category) stainless steel, offering general-purpose corrosion resistance, often in decorative applications.

A term used to refer to various press forming operations in coining, embossing, blanking, and pressing.

Statistical Process Control (SPC)
A technique used to predict when a steelmaking function's quality may deteriorate. By tightly monitoring the product's variance from specifications, the operator can determine when to apply preventative maintenance to a machine before any low-quality (secondary) steel is produced.

Steam Blued
(See Bluing)

Steckel Mill
A reversing steel sheet reduction mill with heated coil boxes at each end. Steel sheet or plate is sent through the rolls of the reversing mill and coiled at the end of the mill, reheated in the coil box, and sent back through the Steckel stands and recoiled. By reheating the steel prior to each pass, the rolls can squeeze the steel thinner per pass and impart a better surface finish.

An iron-base alloy, malleable in some temperature range as initially cast, containing manganese, usually carbon, and often-other alloying elements. In carbon steel and low-alloy steel, the maximum carbon is about 2.0%; in high-alloy steel, about 2.5%. The dividing line between low-alloy and high-alloy steels is generally regarded as being at about 5% metallic alloying elements. Steel is to be differentiated from two general classes of irons: the cast irons, on the high-carbon side, and the relatively pure irons such as ingot iron, carbonyl iron, and electrolytic iron, on the low-carbon side. In some steels containing extremely low carbon, the manganese content is the principal differentiating factor, steel usually containing at least 0.25%; ingot iron contains considerably less.

Steel Intensity
The amount of steel used per unit of gross domestic product. Intensity reflects the secular demand for steel, as opposed to cyclical demand. The amount of steel used in vehicles and the popularity of alternative materials affect the intensity, or how much steel is needed per unit produced. The state of the economy, however, determines the number of units.

Steel Strapping
Banding and packaging material that is used to close and reinforce shipping units, such as bales, boxes, cartons, coils, crates, and skids.

Steel-Intensive Products
Consumer products such as automobiles and appliances that, because so much of their weight is from steel, exhibit a high demand correlation with steel.

Sterling Silver
A silver alloy containing at least 95.2% Ag, the remainder being unspecified but usually copper.

Steel sheets or strip adhering. Usually by fusion spots caused by overheating during box annealing.

A distributor of semi-fabricated products who holds stock for sale to consumers.

An iron alloy. A term indicating a group of stainless steels the principal alloying element of which is chromium in varying amounts from 4.00 to 27.00%.

A measure of the change in the size or shape of a body, referred to its original size or shape. Linear strain is the change per unit length of a linear dimension. True strain (or natural strain) is the natural logarithm of the ratio of the length at the moment of observation to the original gauge length. Conventional strain is the linear strain referred to the original gauge length. Shearing strain (or shear strain) is the change in angle (expressed in radians) between two lines originally at right angles. When the term strain is used alone it usually refers to the linear strain in the direction of the applied stress.

Strain Aging
Aging induced by cold work.

Strain Hardening
An increase in hardness and strength caused by plastic deformation at temperatures below the re-crystallization range.

Properties related to the ability of steel to oppose applied forces. Forms of strength include withstanding imposed loads without a permanent change in shape or structure and resistance to stretching.

Deforming force to which a body is subjected or the resistance which the body offers to deformation by the force.

Occurs during the thermal cutting of high carbon and alloy steels at the cut edges. proper processing, which may include preheating, will prevent this problem

Stress-Corrosion Cracking
Failure by cracking under the combined action of corrosion and stress, either external (applied) or internal (residual). Cracking may be either intergranular or transgranular, depending on the metal and the corrosive medium.

Stress Relief
Low temperature annealing for removing internal stresses, such as those resulting on a metal from work hardening or quenching.

Stress Relieving
Heating to a suitable temperature, holding long enough to reduce residual stresses and then cooling slowly enough to minimize the development of new residual stresses.

Stress-Rupture Test
A tension test performed at constant temperature, the load being held at such a level as to cause rupture. Also known as creep-rupture test.

Stretch Forming
A process of forming panels and cowls of large curvature by stretching sheet over a form of the desired shape. This method is more rapid than hammering and beating.

Stretcher Leveling
Leveling where a piece of metal is gripped at each end and subjected to a stress higher than its yield strength to remove warp and distortion. Sometimes called patent leveling.
It is a method of making metal sheet or strip dead flat by stretching.

Stretcher Straightening
A process for straightening rod, tubing, and shapes by the application of tension at the ends of the stock. The products are elongated a definite amount to remove warpage.

Stretcher Straining
Steel pulled beyond its yield point leaving a distorted surface; also called coil breaks.

Stretcher Strains
Elongated markings that appear on the surface of some materials when deformed just past the yield point. These markings lie approximately parallel to the direction of maximum shear stress and are the result of localized yielding Same as Luders lines.

Striking voltage

The minimum voltage at which any specified arc may be initiated.

Thin, flat steel that resembles hot-rolled sheet, but it is normally narrower (up to 12 inches wide) and produced to more closely controlled thicknesses. Strip also may be cut from steel sheet by a slitting machine (see Sheet Steel ).

Strip Steel (cold rolled)
A flat cold rolled steel product (Other than Flat Wire) 23 15/16 and narrower; under .250 in thickness, which has been cold reduced to desired decimal thickness and temper on single stand, single stand reversing, or tandem cold mills in coil form from coiled hot rolled pickled strip steel.

Steel product group that includes I-beams, H-beams, wide-flange beams and sheet piling. These products are used in the construction of multi-story buildings, industrial buildings, bridge trusses, vertical highway supports, and riverbank reinforcement.
Structural Steel Sheet
When this term is applied to steel sheet, it refers to the designation that is used for steel sheet that is produced to meet a specific level of strength and formability. The formability is expressed as percent elongation in a tensile test. Structural Steel is typically used for applications where the strength of the sheet is an important design criterion, i.e., load-bearing applications.

The arrangement of parts; in crystals, especially, the shape and dimension of the until cell, and the number, kinds and positions of the atoms within it.

Sub-boundary Structure (subgrain structure)
A network of low-angle boundaries (usually with misorientations or less than one degree) within the main grains of a microstructure.

Subcritical Annealing
An annealing treatment in which a steel is heated to a temperature below the A1 temperature and then cooled slowly to room temperature.

A portion of a crystal or grain slightly different in orientation from neighboring portions of the same crystal. Generally, neighboring subgrains are separated by low-angle boundaries.

Submerged-arc welding
Metal-arc welding in which a bare wire electrode or electrodes are used; the arc or arcs are enveloped in a flux, some of which fuses to form a removable covering of slag on the weld.

Substitutional Solid Solution
A solid solution in which the solvent and solute atoms are located randomly at the atom sites in the crystal structure of the solution.

The layer of metal underlying a coating, regardless of whether the layer is base metal.
Raw material used as an input for steel processing: For example, hot-rolled steel is the substrate for cold-rolling operations.

The reaction of a metal or alloy with a sulphur-containing species to produce a sulphur compound that forms on or beneath the surface of the metal or alloy.

Sulfide Stress Cracking
Cracking of a metal under the combined action of tensile stress and corrosion in the presence of water and hydrogen sulphide (a form of hydrogen stress cracking.)

Sulfur (S)
(Chemical symbol S) Element No. 16 of the periodic system; atomic weight 32.06. Non-metal occurring in a number of allotropic modifications, the most common being a pale-yellow brittle solid. In steel most commonly encountered as an undesired contaminant. However, it is frequently deliberately added to cutting stock to increase machinability.

An alloy developed for very high temperature service where relatively high stresses (tensile, thermal, vibratory, and shock) are encountered and where oxidation resistance is frequently required.

Cooling to a temperature below that of an equilibrium phase transformation without the transformation taking place.

Superficial Rockwell Hardness Test
Form of Rockwell hardness test using relatively light loads which produce minimum penetration. Used for determining surface hardness or hardness of thin sections or small parts, or where large hardness impression might be harmful.

Surface-fusion welding
Gas welding in which a carburizing flame is used to melt the surface of the parent metal which then unites with the metal from a suitable filler rod.

Sustained backfire
Retrogression of the flame into the blowpipe neck or body the flame remaining alight.
Note: This manifests itself either as "popping" or "squealing" with a small pointed flame issuing from the nozzle orifice or as a rapid series of minor explosions inside.