Fumblefingers Posted November 10, 2014 Share Posted November 10, 2014 I have a Crabb anglo - 1960s vintage - which has an odd countersunk machine screw in place of one end bolt. Needless to say, it's not feeling too good when I tighten it, hopefully because it's too small a diameter. I may have to replace the nut if the thread has been damaged. Any ideas on supplies/diameters/threads welcome. The instrument is presently air-tight, but the end needs to come off to re-fix the woodwork securing the strap, and I'm reluctant to do it before sorting the end bolt problem. Link to comment Share on other sites More sharing options...
Geoffrey Crabb Posted November 11, 2014 Share Posted November 11, 2014 PM sent Geoffrey Link to comment Share on other sites More sharing options...
Stephen Chambers Posted November 11, 2014 Share Posted November 11, 2014 I think it's likely to be a 7BA thread on a 1960's Crabb, but Geoff will know best. Link to comment Share on other sites More sharing options...
Fumblefingers Posted November 12, 2014 Author Share Posted November 12, 2014 Thanks Stephen - I guessed it would be a BA thread from the 1960's, and Geoff has confirmed 8BA. This box isn't in too bad a way with itself, but I'm hoping to do a decent restoration to as near original as possible. Link to comment Share on other sites More sharing options...
Stephen Chambers Posted November 12, 2014 Share Posted November 12, 2014 Thanks Stephen - I guessed it would be a BA thread from the 1960's, and Geoff has confirmed 8BA. OK, I guess that's what they used on the new ones then, but I can remember being told, way back when, that the (slightly thicker) 7BA could be used as replacement end bolts, - and I did lend my 7BA taps to a certain concertina maker (not Geoff, I hasten to add) many years ago, but I don't think I ever got them back... Link to comment Share on other sites More sharing options...
OLDNICKILBY Posted November 12, 2014 Share Posted November 12, 2014 We, thats Proops Brothers , have them in stock at £4.50 a set including post and packing. A bit more for non- U K. So there is no need to feel deprived of your B A fix Link to comment Share on other sites More sharing options...
Geoffrey Crabb Posted November 12, 2014 Share Posted November 12, 2014 Thanks Stephen - I guessed it would be a BA thread from the 1960's, and Geoff has confirmed 8BA. OK, I guess that's what they used on the new ones then, but I can remember being told, way back when, that the (slightly thicker) 7BA could be used as replacement end bolts, - and I did lend my 7BA taps to a certain concertina maker (not Geoff, I hasten to add) many years ago, but I don't think I ever got them back... You are quite right Stephen, 7BA were used as replacements as an alternative fix if a bellows 'nut' was stripped or when 8BA were not available. Even 6BA with the heads turned down to match the other bolts on occasion (not recommended). At one time during the mid 1970's all odd sizes of BA were discontinued except to special order and were they expensive . Still, I believe that that situation was reversed fairly quickly . And an important lesson learnt then Stephen. Geoffrey Link to comment Share on other sites More sharing options...
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