The hollow drill: making drilling cleaner and more efficient

01. February 2019

There are grants for dust protection through hollow drills with integrated vacuum holes, and for good reason: protecting health and saving time.

Hollow drills are drill heads with an integrated longitudinal channel. The drill dust is therefore extracted directly from the drilling tip through the adapter while it drills. The user therefore avoids coming into contact with the dust. These drills will become more commonplace in future.

hollow drill

The four most important reasons for using hollow drills are:

  • improved occupational safety as splinters and dust are not dispersed into the air
  • saving time as the drill hole no longer requires cleaning and brushing
  • a cleaner workplace as the drill dust is immediately extracted
  • secure anchorings as drill dust inside the drill hole reduces the effectiveness of fixings

Here at fischer we are convinced of this technology and we offer a system with multiple product variants that are compatible with standard hoovers.


Why drilling causes dust

Drills with a drill flute are a relatively recent development.  For centuries tradespeople used drill rods that were only sharpened at the tip.  The advantages: Very clean drill holes that won’t fray, no canting and easy to resharpen. The disadvantages: The drill dust remained in the bore hole and had to be removed at regular intervals during deep drillings.

Drill heads with a drill flute enable one-step drilling because the debris and drill dust is mostly transferred to the surface during the drilling process thanks to the high-speed mechanical power.  Wearing protective eyewear is essential when working with modern high-performance drilling machines in order to prevent injury through any drill dust that shoots out. Fine particles must also be taken into account, as it obscures the user’s view, contaminates the wider surroundings and can potentially damage respiratory tracts.

More Informaton about the FHD

fischer hollow drill

Drilling without a drill flute

Ideally they will have had a helping hand at their side to hold the vacuum cleaner while drilling, but otherwise tradespeople had to work with protective eyewear and respiratory protection in order to prevent being harmed by mineral dust or hazardous substances. In addition to creating dust, the frictional heat in the drill hole can also create uncontrollable by-products depending on the material. In general, every drill hole dirties the outside and inside of the drill, the work gear and the surroundings. This will no longer be the case thanks to hollow drills. Changing to a drill rod without a flute only requires getting used to the appearance. The drill will still have the same effect.  Anyone who uses a system such as fischer’s FHD hollow drill for the first time will think that drilling a hole is far too easy due to the lack of drill dust as well as spectacular clouds of dust.

Hollow drills ensure everything runs smoothly

One of the hollow drill’s additional side effects is that it reduces the risk of the drill head from boring in sideways or getting stuck somewhere. This increases both the level of safety and the possible applications in various different types of material.

Without the drill dust having to be transported through the entire drill hole and past the drill of conventional hammer drills there is less of an emery effect and no additional loss of friction. Drill holes are therefore cleaner overall, including on the inside.

More Informaton about the FHD


Drilling dust – an underestimated risk

The adverse health effects that can be caused by drill dust are just one of the several risk factors. Similar to the way that flour is used during baking in order to prevent the dough from sticking to a tin, the drill dust can drastically reduce the friction between an anchor and the construction material.  Dr. Christian Schlenk, a chemist at fischer who has tackled these issues, has proven that the load-bearing capacity of drill holes that have been cleaned insufficiently can be reduced by up to 50 per cent. This applies to both mechanical and chemical fixings.

The dust settles in a separating layer between the anchoring and the mortar. The effects of gravity cause an uneven distribution in horizontal drill holes, turning the calculation of retention forces into a game of roulette.

Drilling dust in coarse-grained materials also prevents the anchors from being placed at the correct embedment depth due to the bore hole being blocked. Professionals have thus far been brushing and cleaning out drill holes with air, however this causes additional drill dust which gets between the teeth, scratches the throat and stings the lungs.

fischer drill

Fine particles right in front of us

One type of dust is not like the other. Anything that flutters to the floor is relatively unharmful when it comes to most materials. Particles and fibres that continue to float in the air for a long time can irritate the eyes, mucous membranes, skin and respiratory tracts. Without external influences such as wind, heat or electrostatics it can take seven hours or longer for a speck of dust just 1 micrometre in size to sink to the floor.

Anything that is smaller than 10 micrometres is rated inhalable. Our natural filters and cleaning systems in our noses, throats and lungs can take care of certain types of dust themselves, but fine particles (alveolar dust) that are smaller than 2 micrometres can reach the lower respiratory tract and the pulmonary alveoli – where they will remain.

Mineral dust and quartziferous dust can therefore lead to silicosis (pneumoconiosis). These conglomerates and others consisting of finely ground chemicals can even cause damage to genetic material or cause cancer. More information can be found in the Technical Rules for Hazardous Substances (TRGS 559 – mineral dust, TRGS 900 – air limit values, TRGS 903 – biological limit values and TRGS 905 – list of carcinogenic substances) as well as in the ATEX directive. The German Research Foundation also regularly publishes the List of MAK and BAT Values.

Dust protection or dust containment?

Tradespeople must protect themselves against dust as much as possible. While there are sophisticated respiratory devices, they always impair mobility and sight and are unsuitable for high temperatures.

It is better to contain the dust at its point of origin

A vacuum drill is a drill head and vacuum pipe in one.  The drill dust is extracted evenly through an internal channel without clogging it. This means that there is no need to clean the bore hole with a brush or by blowing out the drill hole if the hollow drill is regulated by the ETA assessment of chemical fixing solutions. The cleaning effect was optimised in such a manner that it complies with the fixing system standards.

Using a hollow drill reduces the required time by up to 40 per cent when working with components with dozens or even hundreds of drill holes – all without requiring additional labour resources.

hollow drill FHD

Grants for hollow drills

BG Bau, the German insurance association for the construction industry, provides financial support for occupational safety measures and acquisitions. fischer’s vacuum drills constitute an investment which you can apply for a grant for through BG Bau. In Germany you can apply for a bonus of up to 200 euro for our hollow drill. More information on this subject can be found here.

Is changing to vacuum drills worthwhile?

Vacuum drills were developed in order to be used by professionals. The time saved by using the drill and the level of cleanliness become particularly noticeable with a high degree of utilisation. Changing to vacuum drills does not require any special training as the drilling system remains the same. Attaching the vacuum adapter is self-explanatory and the hollow drill’s centring tip enables drilling on smooth surfaces without slipping. Hollow drills do not require any additional accessories. Suitable M-Class vacuum cleaners should already be part of the standard equipment. They feature a filter that extracts substances that present a medium health hazard.  They also measure the air velocity within the vacuum cleaner. There is no need to clean the drill hole with brushes, air pressure devices or blow nozzles.

fischer hollow drill

Versatile uses: hollow drills are suitable for all dry materials which do not clump together or melt during drilling.  

Your advantages at a glance

  • drill while simultaneously cleaning the drill hole
  • secure and dust-reduced fixings
  • reduced drill jamming
  • less drill dust in the air no matter which angle you drill from
  • with SDS Plus and SDS MAX attachment
  • drill head with centring tip for a clean approach
  • wear marks help identify the wear limit
  • Cleaning brushes, blow pumps and air pressure systems are no longer required if the hollow drills are regulated by the ETA assessment of chemical fixing solutions.