I have fitted a few Velux roof window blinds and I’ve never had any problems with the screws before. The screws supplied with my most recent purchase were very difficult to screw into the wooden window frame. I didn’t use a power screwdriver and toyed with the idea of drilling pilot holes. I eventually opted to replace the cheap Phillips head screws with my own supply of shorter sharper pointed screws which made the job much less physical, especially when fixing the blind to a window in a high vaulted roof, on a very tall ladder.
