Hardware merchandising (January-June 1902) . nd hencethe name. Neither is it iron, as all thebetter grades have for years been made ofsoft steel. HOW IT IS MADE. A brief account of the process of manu-facture may interest some of those who useor handle galvanized iron. The roughly rolled steel bar, or tinplatebar, as it is usually called, which formsthe raw material, is cut to lengths equal tothe width of sheet wanted, heated in afurnace, and rapidly passed backward andforward through the rolls until reduced tothe required gauge. When partly reducedin thickness, the sheets are folded over andr
Hardware merchandising (January-June 1902) . nd hencethe name. Neither is it iron, as all thebetter grades have for years been made ofsoft steel. HOW IT IS MADE. A brief account of the process of manu-facture may interest some of those who useor handle galvanized iron. The roughly rolled steel bar, or tinplatebar, as it is usually called, which formsthe raw material, is cut to lengths equal tothe width of sheet wanted, heated in afurnace, and rapidly passed backward andforward through the rolls until reduced tothe required gauge. When partly reducedin thickness, the sheets are folded over androlled double, and thte/may be repeatedmore than once, so thatjsome of the thinnergauges are finished inljpacks of as many aseight sheets. These\j6acks after cooling offare sheared to the/proper size, the sheetsseparated, annealed, and flattened by coldrolling or stretcl They are therj pickled, the acid cleaned off,and they entajthe galvanizing bath whichis filled with\Anolten zinc with a small per-centage of tjn to produce a bright TWO SYSTEMS OF GALVANIZING It will be seen that there are many pointsin which sheets may vary- the class of steelused, care in the rolling, annealing, pickling,and flattening—but nothingis more important than thegalvanizing, for on that de-pends the life of the are two distinct syterns in use—the flux pcess, in which the shepasses out of the galvaing bath through a flux aretains all the zinc thathas taken up, and the nflux process, in w^ich1sheets pass throuwhich remove partmetal. The latter 1cheaper process andnot produce so sinpotbright a surface agalvanizing, and wbatthe greatest importancoating is uneven arust through muchquickly. Non-flux sheets can beeasily distinguished by thetiger marks, or whitishstreaks running across thesheet, showing where it hasbeen pinched in the rollsafter galvanizing. Thesestreaks turn black soon afterexposure and will be the first parts of thesheet to rust. in The Ironmonger diary for 1902.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectimpleme, bookyear1902
