Steel lintel and curtain poles

DPR87

Hi all, looking to put some curtain poles up upstairs. 
I recently fitted some blinds downstairs and had to drill upwards through steel lintel to get them up.

So upstairs, i've been around the window with a detector and its detecting metal running uo both sides of the window in addition to the top. I thought I would be lucky enough to miss any lintel when drilling 15 cm either side.
Is this standard or should I considering whether these are pipes or wires?

House was built in the 90's
Thanks all

stuart45

You will have wall ties, frame fixings  and angle beads running up the jambs.

Homer_home

I'm confused 

You're looking to fit curtain poles yet you are using a metal detector on the sides of the window?

Why?

Just put the poles where you want them , if you have to drill into the lintel you have to drill into the lintel , it's straightforward enough using the right bit and the right drill 

weeg

Standard minimum lintel bearing is 15cm, so go a bit wider than this you should be fine.