NEW STEELS CUT TOOL AND MATERIAL COSTS.

Dean, Smith & Grace, a machine tool builder in Keighley, Yorkshire, has switched from a proprietary make of free-cutting alloy steel to a new 817M40T (heat-treated) steel known as IQ (improved quality) for manufacturing various machine transmission components. Initial tests carried out by DS&G on IQ steel were performed on 75 and 160 mm diameter bar. Cutting speeds for turning were raised from the 350 ft/min maximum found practical with standard (untreated) 817M40T to the 550 ft/min consistently used for the original proprietary steel. The original feed rates and depths of cut were restored; and the results were, says DS&G, satisfactory. Tool life was increased by as much as 300 percent, compared with that obtained when cutting standard 817M40T, and tolerances for size, geometry and surface finish could be held.