Taconite

What?

Natural mineral containing less than 30% iron. It is the primary ore used in blast furnaces.

Why?

Domestic supplies of iron-rich ores (greater than 50% iron) were largely depleted in the 1940s, so integrated steel companies now process the lower grade taconite to make it useful.

Tailored Blanks

A section of sheet or strip that is cut-to-length and trimmed to match specifications for the manufacturer’s stamping design for a particular part. Because excess steel is cut away (to save shipping costs), all that remains for the stamper is to impart the three-dimensional shape with a die press (see Blanking).

Tandem Mill

A type of cold-rolling mill, the tandem mill imparts greater strength, a uniform and smoother surface, and reduced thickness to the steel sheet. Unlike the original single-stand mills, a tandem mill rolls steel through a series of rolls (generally three to five in a row) to achieve a desired thickness and surface quality.

Tantalum 5

An exotic alloy having high corrosion resistance; used for medical implants, chemical process equipment, and aerospace engine components.

Tap-to-Tap Time

The length of time between successive melting cycles or heats.

Teeming

Pouring; ingot molds are filled (teemed) by iron-bearing ladles.

Tee Splitting

Involves splitting metal beams. Tee straightening is the process of straightening split beams.

Temper Mill

A type of cold-rolling mill, usually with only one or two stands, that finishes cold-rolled, annealed sheet steel by improving the finish or texture to develop the required final mechanical properties. By changing the rolls of the temper mill, steel can be shipped with a shiny, dull, or grooved surface.

Terne

Sheet steel coated with a mixture of lead and tin. Terne principally is used in the manufacture of gasoline tanks, although it also can be found in chemical containers, oil filters, and television chassis.

Tin Mill

Continuous tin-plating facility to produce tin mill steel sheet to be used in food and beverage cans and other containers.

Tin/Chrome Plating

A plating process whereby the molecules from the positively charged tin or chromium anode attach to the negatively charged sheet steel. The thickness of the coating is readily controlled through regulation of the voltage and speed of the sheet through the plating area.

Tin-Free Steel

Chromium-coated steel. Because it is used in food cans just like tin plate, it ironically is classified as a tin mill product. Tin-free steel is easier to recycle because tin will contaminate scrap steel in even small concentrations.

Thin sheet steel with a very thin coating of metallic tin. Tin plate is used primarily in canmaking.

Titanium

Titanium and its alloys have very high strength-to-weight ratios. At normal temperatures, they have high resistance to corrosion. Used primarily in aerospace and chemical processing applications.

Tolerances

A customer’s specifications can refer to dimensions or to the chemical properties of steel ordered. The tolerance measures the allowable difference in product specifications between what a customer orders and what the steel company delivers. There is no standard tolerance because each customer maintains its own variance objective. Tolerances are given as the specification, plus or minus an error factor; the smaller the range, the higher the cost.

Toll Processing

The act of processing steel for a fee (“toll”). Owners of the steel sheet may not possess the facilities to perform needed operations on the material (or may not have the open capacity). Therefore, another steel mill or service center will slit, roll, coat, anneal, or plate the metal for a fee.

Tool Steels

Steels that are hardened for the use in the manufacture of tools and dies.

Ton

Unit of measure for steel scrap and iron ore.

Gross Ton: 2,240 pounds.

Long (Net) Ton: 2,240 pounds.

Short (Net) Ton: 2,000 pounds. Normal unit of statistical raw material input and steel output in the United States. 

Metric Ton: 1,000 kilograms. 2,204.6 pounds or 1.102 short tons.

Tubing

When referring to OCTG, tubing is a separate pipe used within the casing to conduct the oil or gas to the surface. Depending on conditions and well life, tubing may have to be replaced during the operational life of a well.

Tundish

The shallow refractory-lined basin on top of the continuous caster. It receives the liquid steel from the ladle, prior to the cast, allowing the operator to precisely regulate the flow of metal into the mold.

Tungsten Materials 5

Include tungsten and tungsten carbide powders, sintered tungsten carbide products and cutting tools for the metalworking, mining, oil and gas, and other industries requiring tools with extra hardness.

Tunnel Furnace

Type of furnace whereby stock to be heated is placed upon cars, which are then pushed or pulled slowly through the furnace.

Twin Milling 3

Grinds one or all six sides of a small square or rectangular piece of aluminum plate into close tolerance.

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