How Cold Finished Bars are Produced
Cold drawing, consists of drawing a descaled bar of hot rolled steel through a die of the desired size and shape on a "draw bench."
TURNING
Turning consists of removing the surface of the hot rolled bar in a turning machine. The operation is the exact opposite of turning on a lathe in that the tool revolves around the bar, and the bar feeds instead of the tool. Bars are usually polished after turning.
GRINDING AND POLISHING
A ground surface finish is obtained by centerless grinding. The grinding operation is usually followed by a polishing operation.
ELEVATED TEMPERATURE DRAWING ("E.T.D."®)
Elevated temperature drawing is an advanced method of producing mechanical properties in steel bars patented by Niagara LaSalle. Bars are drawn through dies at preselected temperatures significantly above ambient temperature but under the lower critical temperature.
THERMAL TREATMENT
Many applications require strengths or other qualities not available in the ordinary cold finished condition. Annealing, normalizing, heat treating, quench and tempering, electric resistance heating, and stress relieving are treatments that can be employed in conjunction with either cold drawing or turning where special purpose steels are required.
COMBINED PROCESSING
Many of these methods can be combined to produce materials with specific qualities or properties.