Stuck bolts on drain cover

[Robson77]

Hi Everyone.

I'm trying to remove some drain covers in the garden. Some of the bolts seem to have seized and I'm wondering the best way to get them open. I tried a handheld screwdriver but no joy. I was considering the impact driver, but I'm not sure if this will knacker the threads/ bolt head. Any suggestions? Picture below.
Cheers, Rob.

 

[polesapart]

Buy a bigger screwdriver (seriously!) that as close as possible matches the screw slots.

The screws/bolts look like stainless steel (otherwise they'd be rusted to f**k) which is good news. Some silicone grease on the threads while refitting would not go amiss.

 

[Robson77]

Thanks buddy. I got a bigger screwdriver then read your message! It has worked sort of. The only problem I have now is several bolts are just rotating and not coming up (and the cover is still locked in). I got one out with leverage and pliers, still working on the others.