b'CNC machines loaded with indexable tools are the foundation of modern machining.By Christopher Tate Before inserts, cutting tools had to be sharp-ened when dulled. This required them to be re-O ver time, innovative products and ideasmoved from a machine tool and transported have been introduced that significantlyto another location where someone would altered the landscape of machining. Screw cut- manually grind them to restore cutting edges. ting lathes, EDMs, CNCs, CAD/CAM softwareToday, we recognize the disadvantages of hav-and lasers are all milestone technologies oning to take off tools for sharpening. Increased the manufacturing timeline. tool inventories, lost production and longer Inthe1920s,scientistsandengineerssetup times are just some of the downsides. brought cemented carbides to the market.The introduction of carbide inserts changed all That substantially affected the path of met- this. A person now simply indexes, or turns, an alcutting, not only boosting productivity butinsert to a fresh cutting edge or replaces a fully changing machine tool design. Shortly afterworn insert, and a machine tool is ready to run cemented carbides arrived, so did the tools wewith no setup and minimal adjustment.commonly refer to as inserts. Variety is another advantage of carbide in-CNC machine tools, EDMs and lasers are farserts. Before, tools were typically solid HSS or more exciting than carbide inserts, and it is easyhad steel shanks with carbide pads brazed on to see how these technologies have helpedthe end. Variation in workpiece materials re-manufacturing. However, the common carbidequires variation in cutting tool materials. So HSS insert may well have had a much larger impactand brazed tools are manufactured with differ-than all the other developments combined. ent recipes, thereby producing multiple grades 62JULY 2019 Inserts.indd 62 6/13/19 4:12 PM'