DELTA-F

You do all know the traditional Forstner drill bit. In 1874 it was invented by the American Benjamin Forstner, who was born in Beaver County, Pennsylvania. B. Forstner was a gunsmith, inventor and dealer of textile goods.

At that time it was customary, that drills for wood were produced with a centre point, working like a wood screw. Once located and turned, the drill bit pulled itself more or less without any effort into the wood. Perfect for through boring. But what to do, if you wanted to drill e.g. a stud hole, like for a weapon?

For this B. Forstner invented a drill bit with centre point, which was not pulling itself into the material. Beside two main cutting edges these drill bits were fitted with two closed circumferential cutting edges.

Nowadays the power drills and cordless drills are working with a substantial higher speed than in Benjamin Forstner’s day. The professional user is treating surfaces, which are much harder than in that time. Traditional Forstner drill bits with closed circumferential cutting edge and fixed centre point are overstressed and the results are very often blazing hot Forstner bits, which start to smoke during application. Completely different with the cylinder head drill bits with the Bormax geometry. It happens very often, that drillings below an angle of 90° are not wanted. We call this “create an oblique hole“. For this application the fixed centre points are not useful. The Bormax® Prima is a great solution for that.

The Bormax is made of alloyed tool steel. Instead of the fixed centre point it has a drill hole. The enclosed centre point or the pre-drill, which is also included in the scope of delivery, can be inserted into the hole. Two in reverse order staggered, grooved main cutting edges are doing the cutting of the wood. So you have an ideal spreading of the cutting forces. Bevor the main cutting edges can start their work, the so called taper taps have to do the first cuts into the wood. The result is a proper surface of the hole frame without any tearings. The traditional Forstner bit has a closed circumferential cutting edge. This causes higher temperatures and friction. In order to avoid this completely, the Bormax has new circumferential cutters with grooves.

These are working like many small taper taps. The head of the Bormax is fitted with fins, which have the effect of cooling fins. The result is a maximum reduce of the heat development. Before the shank of the tool was cylindrical, now it is manufactured hexagonal.

This avoids that the drill bit turns in the drill chuck. It has proved particularly successful with larger diameters. The Bormax^® Prima version is available in metrical sizes of Ø 15 mm – 50 mm. We also offer different sets.

The Bormax® Prima is a universal drill bit for many different kinds of wood. In case it is fitted with the enclosed centre point, you can hardly differ it from a “normal” Bormax. For drilling wood head pieces, you can mount the tip so, that it protrudes a bit more from the drill head. The Bormax gets better guided, which is especially desirable for drilling in wood head. In case the rings of the wood head are differently hard, we recommend to exchange the centre point with the enclosed pre-drill. With the mounted pre-drill you can also spot-drill your wood surfaces in almost all angles, without gliding off. Drilling on the edge of the workpiece is also perfectly possible.

 

Whatever you use, either the pre-drill or the centre point, you can drill without effort in all common soft woods now. When working on European hard wood it really shows its teeth. In the first cut the many taper taps perfectly cut the long wood fibres and you get an especially proper frame of the hole. More or less without effort the two main cutting edges (from Ø22 mm, smaller Ø are only fitted with one main cutting edge) cut the solid wood. The chip breaking grooves on the main cutters make the chips small and lead to a perfect removal. This tricky geometry makes a clear less feed force necessary in comparison to traditional tools. Even in hard wood the Bormax keeps cool. You will not experience a „smoking“ or „burning“ at Bormax. Not even when working with MDF material or uncoated chipboard. Same for many plastic materials as e.g. polypropylene, polyethylene, PVC and others.

 

You can use the Bormax freehand with a cordless drill as well as stationary. All diameters can be used perfectly freehand with the strong cordless drills of today. All Bormax drill bits are fitted with hexagonal shank and therefore do not turn in the drill chuck.

The Bormax^® Prima is the only Forstner drill bit with exchangeable centre point/pre-drill - beside the long version of Bormax® Prima-, with toothed main cutting edges and a circumferential cutter with grooves. This geometry is patent-protected. It is manufactured in Remscheid and therefore a “Made in Germany“ tool. Due to these unique selling points it belongs to the DELTA-F family of FAMAG.

 

 

• precise setting and perfect guiding properties with inserted pre-drill in freehand operation
• optimum guidance with inserted pre-drill at setting angles other than 90°
• considerably reduced feed force by the perfectly designed centre point and the toothed circumferential cutting edge
• nearly no heat generation thanks to the sophisticated geometry of the interrupted circumferential cutting edge with cooling effect
• very good chip removal due to the chip breakers on the main cutting edges
• due to its geometry it also drills perfectly in European hard wood
• the hexagonal shank avoids turning in the drill chuck
• still has the unique Bormax^® geometry after regrinding
• can be perfectly extended with extensions

Overview of the most important details:

 

Certainly the bestseller is the 5pcs set consisting of Ø 15/20/25/30/35 mm. But also the 8pcs set (Ø 15/20/25/30/35/40/45/50 mm) is very popular. There are 7 sets available in metric dimensions.

 

If you want to drill special deep holes with the Bormax, we can offer extensions with overall lengths of each 80/125/250 and 400 mm. These extensions can be used in any order combination. The Bormax can be extended by several extensions of the product line 1639.

 

If you want to produce a stud hole with a defined depth, the depth stop of the product line 1621 can be a perfect supplement. You insert the Bormax (with mounted centre point) into the guide bushing of the depth stop, adjust the drill depth and fix the tool with help of the enclosed allen key.

 

Bormax^® Prima, Long Version
The largest diameter we manufacture of Bormax product line 1624 is 50 mm. For drilling still larger diameters, we recommend the product line 1614, Bormax^®Y Prima long version, with exchangeable pre-drill respectively centre drill. We produce these tools from Ø 20 mm up to Ø of 120 mm.

 

Pre-drill, centre drill, guiding pin and depth stop are available as accessories