Bormax 2.0 prima long

90 mm FAMAG

FAMAG Bormax prima long Series 1614 are a combination of Forstner bits and counterbores.

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

If regulations require it or if an invisible connection is desired, the washer and nut must be recessed into the wood. In practice, the carpenter drills a through-hole in a wooden beam using an auger bit according to the diameter of the threaded rod being used. This is typically softwood or structural wood. To recess the washer/nut, the carpenter uses a counterbore. Counterbores are part of the cylinder head drill family and differ from the classic Forstner or spade bits in that they do not have a fixed centering point. Instead of a centering point, these wood drills have a pilot hole, into which a pilot drill or guide pin can be inserted.

We offer 19 different diameters of counterbores as standard. The smallest diameter is 20 mm and the largest diameter is 120 mm. Counterbores/Forstner bits with diameters from Ø 20 – 40 mm have an 8 mm pilot hole, larger counterbores/Forstner bits have a 10 mm pilot hole. To match these two pilot holes, we offer guide pins ranging from 8 – 22 mm. By the way, FAMAG always manufactures the guide pins „under size”. This ensures very easy and precise guidance and prevents excessive friction in the pre-drilled hole.

The mounted guide pin provides the counterbore with perfect guidance, allowing for freehand drilling in larger diameters than with a drill that has a fixed centering point. As an alternative to the guide pins, 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 counterboring can be done in one operation, 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 borehole. Thus, the Bormax 2.0 prima long keeps a „cool head” even under the toughest conditions.

Counterbores are often used in larger diameters. As the diameter increases, the feed forces also become greater. Since these tools are used freehand, it is desirable to minimize these forces. This is achieved through the new Bormax 2.0 geometry! Offset chip breaker grooves on the main cutters ensure easier and faster drilling. The feed forces are significantly reduced. Included in the delivery is a centering drill (as shown in the image). This centering drill can be pushed into the borehole so that it protrudes very little. However, you can also mount this pilot drill so that it extends further out of the borehole. Then you have perfect guidance and can even drill freehand up to 100 mm with a strong cordless drill in softwood!