I'm new to DIY so forgive my lack of knowledge! Just bought a house and have ordered blinds to fit inside the window recesses. Fitting them involves drilling into the top of the window recess to mount two brackets.
I have a percussion drill (this one) and since it didn't come with masonry bits, I purchased a Bosch drill bit set (this one). Using the 6mm masonry bit from this set (it has the distinctive "hammer-head" look), I attempted to drill a 5cm hole straight up into the lintel and after a few millimeters of soft plaster, I hit either concrete or stone and have been unable to drill any further than 1cm in with around 10 minutes of drilling slowly. Having read around, if the hole takes more than 30 seconds to drill then something's not right.
As far as I know, I'm using the correct drill bit (which hasn't worn although got hot) albeit from a relatively cheap set and I do have the drill set to percussion mode and rotating the bit clockwise. The drill claims to be able to drill holes up to 13mm wide in concrete and so the only things I can think of are that the drill or bit aren't up to the task (though the bit is still intact) or whatever I'm drilling through isn't concrete. I'm 100% certain that the lintel above the window is not wood, as inspecting the hole reveals a hard grey material like stone or concrete.
I guess my question is: is my equipment not up to the task, whether this is because the equipment is cheap or because the equipment I have can't be used to drill into stone?
For information, the house is a former council house built in the 1960's.
Thanks in advance!