80s 1960A speakermounting bolts: size & type?

[Chris - CMW amps]

Hi all

I'm missing the 16 bolts for speakermounting from an 80s Marshall 1960A cabinet.

What type and size do I need? It's not metric (larger than M4, too tight for M5).

Many, many tia!!!

[Steve Conner]

They're probably BA http://www.britishfasteners.com/threads/index.html

If a M5 bolt will thread in but goes tight after a few turns, my guess is that they're 0BA.

I've run a M5 tap through 0BA nuts before in an emergency, but that's really not a good idea with speaker T-nuts :eek: