I know, lurid headline - I apologize!
But that's how amazed I am by the Festool CE Stone masonry drill bits when used with my PDC.
I never ever bought cheap drill bits, but with my rotary hammer and it's drill bits I couldn't (and I can't) get into my walls without hammering (masonry, not concrete). Even the pros that did the hole for the gas line needed a lot of patience with their SDS-Max type rotary hammer and hole cutter. I always knew these walls were hard.
I originally simply tried because I wanted to see what happens, so I used a 6mm CE Stone drill bit from Festool in my PDC and it went right into the wall. I thought I had hit a "soft spot", so I did it again, and again...
Over the last two days I renovated the kitchen, had a ton of 5, 6 and 8mm holes to drill. I drilled all but two of them without hammering, just with the PDC on full speed of course. For the two holes I needed the hammering mode, it was a piece of cake too after changing modes.
Since I also couldn't get into the walls with just the Hawera MultiConstruction drill bits AND the PDC, I strongly assume theres more to the Festool CE Stone drill bits than just the fact that they are running at a extremely high speed in the PDC. Also the fact their tips are made from carbide can't be the sole reason - the MultiConstruction and X5L SDS-Plus drill bits from Hawera also have carbide tips...
I wanted to share this experience - and I really can't recommend these drill bits enough. Great piece of kit - worth every penny.
If someone has more insight on those drill bits and why they are so great - any input would be highly appreciated!