A magnetic core drilling device making gap with annular cutter (Main drill) The term Main drill little bit is utilized for two pretty distinct applications. A countersink is often a conical hole Slash into a manufactured object; a countersink bit (in some cases termed simply countersink) could be the cutter https://drillbitmanufacturer30639.weblogco.com/34420130/little-known-facts-about-drill-bit-supplier