Difference between drilling and milling
Drilling and milling are machining processes in which material is removed from a workpiece to give it the desired shape. The removed material is often referred to as chips.
As the material is removed with geometric cutting edges, both processes belong to the group "cutting with geometrically defined cutting edge".
Drilling
When drilling, the tool rotates around its own longitudinal axis, which creates the cutting movement. Penetration into the workpiece takes place through the feed.
Milling
When milling, the tool also rotates around its own longitudinal axis, which creates the cutting movement. However, in this process, the workpiece usually performs the feed movement by moving the work table. This usually takes place perpendicular to the tool.
Milling a hole or drilling a hole
Sometimes it is said that a "hole has been milled". This expression can easily cause confusion.
1. drilling a hole
Twist drills or core drills are usually used to drill a hole. The hole is made by the feed and the rotating cutting edges of the drill.
2. "Milling a hole"
With centre-ground milling cutters, only the workpiece is "plunged", for example to mill a pocket groove or a slotted hole. The prerequisite for "plunging" is a cutting edge that goes over the centre of the milling cutter (ground over the centre), as is the case with 2-edged slot milling cutters, for example. Accordingly, no real bore or hole is created.
Please note that holes created with a centre-ground milling cutter are not dimensionally accurate.
Why are drill chucks not suitable for milling?
Drill chucks can be used to clamp drill bits in a drilling/milling machine.
Although drill chucks can be used on milling machines, they are not suitable for milling work. During milling, horizontal forces in particular act on the tool and therefore also on the drill chuck, but the latter is only suitable for vertical forces (as with drilling). The three clamping jaws of the drill chuck are not sufficient for the forces that occur, as the clamping surface is very small and the clamping jaws are not designed for this.
However, as our milling machines can also be used as drilling machines and have a quill stroke, drills can be clamped in our machines with the aid of a drill chuck in order to drill holes conveniently and quickly.
