What is not apparent from the description above that these drills are designed for up to 2,000 revolutions. On machines with more than 3,000 rotations and more, as well as very high impact rate (over 50,000 per minute or more), it may happen that the drill burns starting with the cutting tip. That can happen, but it does not.
The cartridge makes a stable impression and closes tightly. The circumferential Hard rubber frame protects them from small bumps, if the cartridge is dropped again. The drills are very well made, especially important here is the cutting tip. (Material: carbide of chrome-titanium)
The drill of Robust Line series are very suitable for drilling in stone / masonry / concrete. They work their way quickly into the material, the well itself is clean and straight without imbalances (straight drills).
My Conclusion:
High-quality masonry drill from very good materials and priced fairly. But a star nonetheless I prefer from, due to the aforementioned maximum possible number of revolutions. As well, the drill hit in continuous use, I will report in the coming weeks.
Update 01: 06.07.2012
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So far, the drills have done a very good service. In the more than 150 holes in masonry and reinforced concrete (all drill sizes) there was no reason for complaint. The blue color has a little relieved but that was in sight. How do the drills continue to hold, I will also note the future. Until then, enjoy hand and DIY.