| A Sheet Metal Screw | (english) Sheet metal screws with (a) sharp-pointed ends; and (b) fewer threads per inch than type AB screws; and (c) deeper threads with bettere gripping power than type AB. The industrial Fasteners Institue incorrectly labes type A an “obsolete” thread though it is universally preferred in 18-8 stainless over type AB, especially by the marine industry. |
| AB Srews | (english) Sheet metal screws with pointed ends similar to type-A screws and thread dimensions similar to type-B. Type AB screws are seldom used in stainless. |
| Acme Thread | (english) A screw thread having a 29 degree included angel. Used largely for feed and adjusting screws on machine tools. |
| Actual Weight | (english) The customer buys by the actual (scale) weight of the steel. The theoretical weight is used in estimating, however, it is not to be used for billing. |
| Agglomerating Processes | (english) "Fine particles of limestone (flux) and iron ore are difficult to handle and transport because of dusting and decomposition, so the powdery material usually is processed into larger pieces. The raw material's properties determine the technique that is used by mills. 1) SINTER Baked particles that stick together in roughly one-inch chunks. Normally used for iron ore dust collected from the blast furnaces. 2) PELLETS Iron ore or limestone particles are rolled into little balls in a balling drum and hardened by heat. 3) BRIQUETTES Small lumps are formed by pressing material together. Hot Iron Briquetting (HBI) is a concentrated iron ore substitute for scrap for use in electric furnaces. |
| Bainite | (english) A eutectoid transformation product of ferrite and a fine dispersion of carbide, generally formed at temperatures below 840 to 930 F (450 to 500 C): upper bainite is an aggregate containing parallel lath-shape units of ferrite, produces the so-called feathery appearance in optical microscopy, and is formed at temperatures above about 660 F (350 C); lower bainite consists of individual plate-shape units and is formed at temperatures below about 660 F (350 C). Also, a slender, needle-like (acicular) microstructure appearing in spring steel strip characterized by toughness and greater ductility than tempered Martensite. Bainite is a decomposition product of Austenite best developed at interrupted holding temperatures below those forming fine pearlite and above those giving Martensite. |
| Basic Oxygen Furnace (BOF) | (english) "WHAT A pear-shaped furnace, lined with refractory bricks, that refines molten iron from the blast furnace and scrap into steel. Up to 30% of the charge into the BOF can be scrap, with hot metal accounting for the rest. WHY BOFs, which can refine a heat (batch) of steel in less than 45 minutes, replaced open-hearth furnaces in the 1950s; the latter required five to six hours to process the metal. The BOF's rapid operation, lower cost and ease of control give it a distinct advantage over previous methods. HOW Scrap is dumped into the furnace vessel, followed by the hot metal from the blast furnace. A lance is lowered from above, through which blows a high-pressure stream of oxygen to cause chemical reactions that separate impurities as fumes or slag. Once refined, the liquid steel and slag are poured into separate containers. " |
| Basic Oxygen Process | (english) (BOP) A process in which molten steel is produced in a furnace by blowing oxygen into molten iron, scrap and flux materials. The furnace is known as Basic Oxygen Furnace (BOF). |
| Basket Screen | (english) A first stage in-line water filter for water delivered from the New Blowing Room Pump Room to the Blast Furnace. The strainer contains an electric-driven rotary sieve that catches particulates and prevents them from entering the water system. |
| Bend Test | (english) Various tests which is used to ascertain the toughness and ductility of a metal product, in which the material is bent around its axis and/ or around an outside radius. A complete test might specify such a bend to be both with and against the direction of grain. For testing, samples should be edge filed to remove burrs and any edgewise cracks resulting from slitting or shearing. If a vice is to be employed, then you must line the jaws with some soft metal, to permit a flow of the metal in the piece being tested. |