Oh I see. I can explain my confusion: They come in two varieties, one is E40 an the other is bayonet (B22). Here in NZ interior home light sockets are sometimes E27 and sometimes B22. I have a couple of the bayonet Philips 40W bulbs here and they do fit a normal socket size, so I figured the screw version would be the normal size as well. But I see you're right that it's a larger size, and I know you guys don't use bayonet. Sorry!