What Is a Drill Grinder?
A drill grinder is a type of grinding tool that specializes in grinding drill tips.
There are two types of drill grinders: drill pointers, which grind the end face, and thinning machines, which grind the web.
One manually applies the drill to the grinding wheel when grinding and one automatically performs grinding when the drill is set. The fully-automatic grinding type can be operated even by unskilled operators because it literally sets the drill and automatically grinds everything.
Uses of Drill Grinders
Drill grinders are mainly used to regrind drills that have been used.
The tip of a typical drill is at 118 to 120 degrees, which when viewed from the side has less cutting resistance.
If the center of the tip’s thinning is off-center, the hole will not be drilled straight and in some cases the drill will break. Therefore, it is necessary to use a drill grinder to accurately grind the drill according to the type of thinning.
Recently, the number of 3-blade drills has been increasing, and there are CNC fully automatic tool grinders that can grind these.
Principle of Drill Grinders
Drill grinders are maintenance machines that use grinding wheels to grind and polish the cutting edges of used drills, thereby restoring the sharpness of the cutting edges and allowing the drills to be reused.
There are different types of drills, such as mountain drills, candle drills, one-letter drills, and chamfer drills. Most drill grinders that can grind according to those shapes are simple in construction, small, and portable, but some are fully automatic drill grinders, machines that can automatically grind a variety of drill shapes. The best grinder should be selected based on the drill shape and application.
Grinding wheels are selected according to the drill material. Tungsten carbide and titanium coated drills mainly use diamond grinding wheels, while HSS drills mainly use CBN grinding wheels.
NC tool grinders are also available with detailed settings for tip angle, thinning angle, compensation value, and grinding amount. These machines can grind end mills and other tools other than drills.