Forstner bit: what speed?

Forstner drills are not used too often as home improvement, but in some applications they make sense. The decisive factor for the Forstner drill is above all the right speed when working. How to choose the right, and when which speed is appropriate, you will find in our article.

Functional principle of the Forstner drill

A Forstner drill works differently than a conventional twist drill. He has at the top of several cutting edges, which work in principle like an ordinary cutter.

The cutting edges on the top, like a planer, chip away from the wood in a chip-to-chip manner, creating a circular countersink in a flat wooden surface.

It is important, of course, that the centering point lies exactly in a predrilled hole, that the cutting edges are sharp and that a precisely measured pressure is exerted on the drill. The best way to use Forstner bits is always in a drill rig, as both the drilling depth and the pressure can be best regulated here.

Pressure and speed

When drilling with the Forstner drill, it is important that the working pressure on the drill and the speed are carefully matched. This requires a little feeling, but is easy to learn in practice.

There is no general information for the speed, the values ​​also depend a little on the device used and the settings and the device performance.

In general, however:

at soft wood at first to about 1200 / min, at hardwood initially not more than 400 / min, unless the drill does not get hot, then can be further increased, In practice - depending on the drill, drill and material - but also up to 3,000 / min for softwood and up to 1,500 / min for hardwood without overheating may be possible, often also brings cleaner results when drilling.

The overheating of the drill should be avoided at all costs. If the drill "glows" it loses its sharpness very quickly, the cooling in water does not help here either. In addition, there is a risk that the wood starts to smoke and later shows unsightly brown marks.

Tips & Tricks

As an alternative to the Forstner drill, you can also use so-called artificial drills. These drills, which work quite similarly and are used for the same purpose, are often carbide-tipped and therefore provide significantly better drilling performance.

Video Board: how to select correct speed for diameter and material | drill press | dave stanton | woodworking