GB695821A - Improvements in or relating to cutting and abrading tools - Google Patents

Abstract

695,821. Milling; planing; making files, milling-cutters, graters, &c. BOOTH, C. H., and HARDWICK, H. B. Sept. 14, 1951 [Nov. 30, 1950], No. 29399/50. Addition to 666,573. Classes 83 (ii) and 83 (iii). [Also in Group XXIII] A cutting element for use as a file, rasp or cutting band or clisc, as described in Specifications 666,621 and 666,622, comprises a thin flexible strip of steel, e.g. mild steel, having holes 10 with cutting edges formed by upset portions of the edges of the holes, theedges having cutting clearance angles relative to the surface of the strip and the strip being surface-hardened (e.g. by cyanide treatment and tempering or by diffusion hardening), so that both surfaces of the edges are hardened without unduly hardening the body of the element. The clearance may be provided by upsetting the sharpened edges themselves, as described in Specification 666,621, or by reversely bending the strip along the rows of sharpened edges and between the rows, as described in Specification 695,830; an element I having the latter type of clearance is shown in Fig. 4. The element 1 may be provided with a concave backing member 3 resting on the longitudinal edges of the element and secured to it by turning up and over the corners 6 of both the element and the backing member. One or more handles may be provided on the upper surface of the backing member. The strip may be flat or of curved cross-section.