Views: 8 Author: Site Editor Publish Time: 2022-07-26 Origin: Site
· Drilling in concrete or reinforced concrete:
Concrete is normally strengthened with the reinforcing steel. When drilling rebar, the drill bit should be raised every 10 to 20 seconds. This ensures that the drill bit is undamaged and, more importantly, the steel chips are removed so that the bit can find a new drilling point. As a result, removal power is increased.
If a rotary hammer drill bit fails when drilling rebar, carbide remains in the drilled hole and this can lead to the failure of another rotary hammer drill bit. Therefore, it is absolutely necessary to start the second drilling tool at slow speed and low pressure and to continue drilling cautiously.
In the case of reinforcement collisions and especially when breaking through reinforcement, the rotary hammer drill bits tend to jam. This can lead to carbide chipping. The pressure on the rotary hammer drill bit and the power of the machine should therefore be reduced when breaking through or if the rotary hammer drill bit begins to jam.
· Drilling in granite or on a reinforcement:
Very high heat is created in the drill bit during drilling. All temperatures > 400°C result in damage to the carbide and brazing. This can lead to breakage or loss of the carbide. Therefore, the drill bit should ideally be cooled or given enough time to cool down.
· Drilling in smooth surfaces:
Spot drilling or center punching to prevent drill bit slippage. We recommend the use of our drill bits with special centering tips.
There are no precise speed specifications for rotary hammer drills. Only recommendations can be made. The following applies in general: the larger the rotary hammer drill, the lower the speed. To achieve fast drilling progress, drilling at the highest speed is recommended, because the impact rate of the rotary hammer drill is normally linked to the speed.
To prevent the machine from jumping, high pressure should be exerted on the rotary hammer drill bit during spot drilling and the machine should be set to the hammer position. Select the pressure on the machine so it does not jump and can work quietly. This is ensured by a pressure of 15 kg to 25 kg. If the pressure is too low, the machine will jump, producing a dead blow. This can result in increased impact energy, which can destroy the drill bit. The rotary hammer drill cannot work properly with excessive pressure. This reduces the service life of the rotary hammer drill and results in increased heat input when hammer drilling.
Before insertion into the machine, the insertion end must be cleaned and then lubricated with drill grease (approx. 0.5–1.0 g). This must be observed, especially when using the tool for the first time. This ensures proper functioning of the tool mount and minimal mounting shank wear.
