End mills less than mm become quite vulnerable and therefore cannot operate as vigorously as a drill. If you need to drill a very deep hole – more than 4 times your hole diameter, choose a drill. Because if the hole diameter exceeds this value, it may be very difficult for the end milling .
Jun 07, 2018· End mills are either center cutting or noncenter cutting. This is basically the tool's ability to cut straight down into a material without requiring a predrilled hole. A centercutting end mill has cutting edges that extend into the center of the tool, which allows it to plunge into a material.