DELTA-F

May be 40.000 years ago the human being invented the drill bit. Over the centuries the drills have been continually improved. One of the really big problems with drilling was to transport the drill material out of the hole. In 1865, at the time of the foundation of FAMAG Werkzeugfabrik, Giovanni Martignoni, a Swiss mechanic, lived in the neighbouring town of Remscheid. He first constructed a drill with twisted grooves after our records. First he filed only one groove into a cylindrical body, later two grooves which were spiral-shaped. From now on the drill material could be transported out of the borehole similar to a screw conveyor. Martignoni’s idea met with great approval and also found the way to America. Already in 1867 American twist drills were presented at the Paris World Exhibition. But actually the invention with this background comes almost from the Bergisches Land; or at least 30 km far away!

In woodworking certainly spiral tools that possessed a polish section of the cone-shaped shell were used first. Twist drills are made of metal, but drills for wood are not made of wood! Much more they differed from the drills for metal by their head geometry. For a better drilling in wood these drill bits were ground with a centre point. In the first FAMAG catalogues there are drills for wood, which even have a kind of taper tap

Today drills for wood are used in the industry, the craft, at home and in numerous trades. The field of materials is wider than ever. We have moist soft woods, European hard woods and exotic hard woods or even rock hard exotic hard wood from far regions. Let us start with taking a look at soft wood and the geometry of the drills: During drilling you produce high cube chips. Moist wood or resin increases the problem of removing the large soft wood chips through the spiral out of the boring. Low cost twist drills are mainly produced through “roll rolling”. This means that spirals are rolled into an unhardened blank by using two metal rollers. Too often these tools do have a brittle and rough surface within the spiral which disturbs the transport of the chips. You all know the result: The chips remain hanging in the spiral and block it. The drill is stuffed. This is especially bad for spiral drill bits with a long working length.

For slightly better tools, the spiral is milled into the unhardened blank. In production, time is money and so the used feeds do also produce rough surfaces in the spirals. The result is similar bad, also these tools stuff. Furthermore, in both manufacturing processes the spirals are only hardened after they were finished. This can lead to a hardness distortion, which can often not be completely eliminated even by a subsequent grinding of the outer geometry. The result are twist drills that do not run smoothly. This is again drastic for working with spiral drills with a long working length. In case you want to have low-cost drills for working in soft wood only, cost-efficient steel grade may definitely be sufficient. For drilling in hard wood or rigid coatings these steel qualities are not at all convenient.

With all these experiences we decided to produce the perfect brad point drill bit for all soft and hard woods – with an impressive result.

If you want to drill in hard woods or coated boards, you reach good results with drilling tools made of high quality material. In our opinion the most suitable material for wood working is high-speed steel (HSS). Therefore the premium brad point drill bits of our product line 1599 are made of HSS. We use a cylindrical HSS blank. After cutting into lengths, the blank is hardened. We grind two spirals into this now hardened piece by means of two grinding wheels. The result of this first manufacturing step is a spiral blank with perfect concentricity.

Selecting the spiral geometry creates another special feature: Usual spirals have the geometry of a semicircle. On the flanks of these semicircle geometry, however, they can later retain well the chips when working with hard wood. We might get chip jam. Thus, our spiral has a geometry similar to a screw conveyor, with the effect that the chips slide through the spiral during drilling without jamming there. This effect is further enhanced by the extremely smooth spiral surface, achieved during grinding. We call this production method “fully ground”.

But also the head geometry of these tools is fully ground! Our CNC machines follow a tricky program, which allows to create the brad point, two main cutting edges and two taper taps. In the following we relief-grind the main cutting edges to reduce friction forces during application.

The result of this production method is a brad point drill bit of the quality class “Excellent”! A tool made of the best of all HSS materials, with a perfect concentricity and a spiral type, which guarantees an excellent transport of the chips. The two taper taps create a perfect drilling hole circle. The two main cutting edges produce a rapid feed, which is favoured by the ideally designed and particularly smooth spiral.

You can drill without any efforts in all hard woods - and even in rock-hard woods - by using these HSS-G brad point drill bits in extra long version of excellent class quality. Best results will be achieved in stationary use. These drills do well with high speeds. For example, we recommend running the Ø 4 mm with an overall length of 150 mm at 5.000 rpm. You reach rapid feed rates with these high speeds with best chip removal. The tools are also suitable for freehand use, but for these extra long tools you need some sensitiveness. It is important that you use a powerful machine with high speeds. Do not try to drill a diameter of 3 mm or 4 mm with 1.000 rpm freehand in soft wood, you will not be happy with the result and you might easily break the drill. The field of application of these long and extra long brad point drill bits of HSS-G is very complex. Here a few examples:

For exact deep-hole drilling in glulam or in beech for wood construction, these HSS-G spiral drill bits with overall lengths of 315 mm and 460 mm are the perfect choice. But also the overall length of 250 mm is increasingly being used here, not least because of the long service life of these tools. Instrument makers however will be happy with smaller diameters of 3, 4 and 5 mm. You have read correctly, we manufacture even the small diameters of 3 and 4 mm in all lengths and also in the length of 460 mm! If you want to make a hole with this small diameter, we recommend to press the brad point carefully into the wood before (!) starting your machine. It is true that drilling those small diameters needs some practice and sensitiveness, but it is quite possible! Writing instruments such as solid wood pens have become increasingly popular in recent years. Root wood shows great grains but is often very tough. Since these tools are made of HSS-G with a great service life, they come just right!

The brad point drill bits made of HSS-G of that product line have several unique selling points. Some carpenters told us, that after the first use of these tools they decided to only use these drills for drilling deep holes with small diameters in future - instead of using auger bits. There are voices claiming, that these are the best drills for “deep-hole drilling” ever. But please make your personal decision for yourself. The positive experiences of the users clearly let us count these tools to the DELTA-F family of FAMAG and they deserve the quality class Excellent!

• high-precision drillings thanks to the fully ground finish
• perfectly suitable for all hard woods due to the use of high quality HSS steel
• especially proper drilling pattern due to two grinded taper taps
• perfect chip removal especially during deep hole drilling due to the fully ground deep hole spiral
• very fast drilling as these twist drills require high speeds and feeds
• available in overall lengths 150/250/315 and 460

Overview of the most important details:

Beside the individual diameters from 3,0 up to 16,0 mm with overall lengths of 150/315 und 460 mm, we produce the overall length of 250 mm up to a diameter of 25 mm. Two sets in a high quality wooden case are available.

The set of 7pcs with diameters 3/4/5/6/8/10 and 12 mm with an overall length 250 mm and the set of 10pcs with diameters 3/4/5/6/7/8/9/10/11 and 12 mm with overall length of 150 mm.

If you want to combine a perfect drill and a countersinking with an angle of 90° in one operation step, we recommend our VARIO countersink. This probably only makes sense for drills with an overall length of 150 mm. The VARIO is fitted with a high quality carbide tipping and can be put on all diameters from 3,0 up to 8,0 mm. Important to mention that this countersink is a two-piece tool, pushing on the drill bit from two sides. As a result, the perfect concentricities of these brad point drill bits are not affected. This is particularly important for the smaller diameters like 3/4 and 5 mm. With the high quality tipping it is ideal for use in combination with the HSS-G brad point drill bits of the product line 1599.1. You will enjoy the high service lifes.

If you need larger diameters than 16 mm, we recommend product line 1599.2. We produce this line up to a diameter of 25,0 mm. For even larger diameters or longer working lengths, you should use the auger bits of product line 1410.