Bormax 2.0 prima long

20 mm FAMAG

FAMAG Bormax prima long Series 1614 are Forstner bits and counterbore bits in one.

When structural timbers need to be joined, there are various methods available. A traditional and popular method is screwing connections using threaded rods or screws, washers, and nuts. There are standards that prescribe the dimension of the washer according to the thread used.

If the regulation requires it or if an aesthetically invisible connection is desired, the washer and nut need to be countersunk into the wood. In practice, the carpenter drills a through-hole in a wooden beam with a twist drill corresponding to the diameter of the threaded rod used. This is typically softwood or structural timber. To countersink the washer/nut, the carpenter uses a counterbore bit. Counterbore bits are a type of cylinder head drill and differ from the classic Forstner or sawtooth bits in that they do not have a fixed centering point. Instead of a centering point, these wood drills have a pilot hole that can accommodate a pilot drill or guide pin.

We offer 19 different diameters of counterbore bits as standard. The smallest diameter is 20 mm and the largest diameter is 120 mm. Counterbore bits/Forstner bits with diameters from 20 mm to 40 mm have an 8 mm pilot hole, larger counterbore bits/Forstner bits have a 10 mm pilot hole. Corresponding to these two pilot holes, we offer guide pins ranging from 8 mm to 22 mm. Incidentally, FAMAG always manufactures the guide pins „undersized.” This provides a very easy and precise guidance and prevents excessive friction in the pre-drilled hole.

The mounted guide pin provides the counterbore bit with perfect guidance, allowing for freehand drilling in larger diameters than a drill with a fixed centering point would allow. Alternatively, pilot drills are also available: 8 mm in diameter for drills up to 40 mm and 10 mm in diameter for drills from 45 mm. In principle, any wood drill with an 8 mm or 10 mm shank can be used. The advantage of FAMAG pilot drills is that they have a clamping surface on the shank for better power transmission. With an inserted pilot drill, drilling and countersinking can be done in one step, saving the time of separate pre-drilling. This combination tool also allows for angled drilling.

New to the Bormax 2.0 prima long is that the circumferential cutters are manufactured with the new Bormax grooves. This significantly reduces friction in the drilling. Thus, the Bormax 2.0 prima long keeps a „cool head” even under the toughest conditions.

Counterbore bits are often used in larger diameters. As the diameter increases, so do the feed forces. Since these tools are used freehand, it is desirable to minimize these forces. This is achieved by the new Bormax 2.0 geometry! The two main cutters have staggered chip breakers which make for easier and faster drilling. The feed forces are significantly reduced. The delivery includes a centering drill (as shown in the image). This centering drill can be pushed into the hole so that it protrudes only slightly. However, you can also mount this pilot drill so that it extends further out of the hole. Then you have perfect guidance and can even drill up to 100 mm freehand with a powerful cordless drill in softwood!