[QUOTE="Nigel"] But I did say ICBW, so it might be worth a phone call / trip to your local Plumb Centre tomorrow (go early, they'll probably shut at lunch time).[/QUOTE] You weren't wrong, not all bleed screws are the same size. I bought an end plug and bleed screw as a set. The screw is smaller than the original one was. I'm hoping that the plug will be the same size though which I won't know until I manage to get the old one out.