On Thu, 08 Oct 2009 22:55:21 +0100, "Dave Plowman (News)"
had this to say:

In article ,
ARWadsworth wrote:
I also have a 4BA tap and some 4BA bolts. Guess what I use to fit
sockets to back boxes where the 3.5 thread is totally knackered?

Other way is to superglue 3.5 nuts to the back of the lug. They can be
difficult to get, though.

It's all such a botch though, isn't it? ALL for the sake of so-called
standardisation. Where does real engineering fit into all of this?

--
Frank Erskine