What is that? A valve core tool? The OP is talking about the nut that holds the whole valve to the rim.
Okay, so I made a mistake
Forgive me
But needle nose pliers aren’t the ideal tool for the nut, either
a 1/4"-drive socket would be a good choice, as already mentioned
The problem with the typical needle-nose pliers is that the jaws don’t open parallel, so you’re not actually getting a good bite on the flats of the nut
Thanks for all the replies! I figured it out now. I bought a thin wall 11mm socket and used a hammer to get it on the screw. Now I can finally inflate the tire.
Interesting. I wouldn’t have guessed that would work for that particular placement. I have an 11 mm wrench that I seem to use for standard sae fasteners pretty often. I’ve never used it for any 11 mm metric fastener, those seem pretty uncommon. 11 mm must be pretty close to a standard sae dimension though.
That’s the best solution. Technically not a screw. It’s a nut. That pic in the OP is ugly looking. Hope it holds air.