Forums, Internal Fixtures and Fittings, saloon table clamps

Brigitte at 06/02/2014 14:34:58
I am in the process of machining a new clamp for the old post style saloon table banjo as we only have the broken off thread of one of them. I know the diameter of the thread is about 8mm but I stupidly forgot to bring the stump home to confirm what flavour of thread I’m dealing with. I called JR and they said it would be an imperial thread, but couldn’t be more specific

I am currently some distance from the boat and not expecting to go back for a couple of weeks so I was hoping that somebody here might be able to enlighten me? I really want to get on with the job.

Any help most gratefully received!

Dolphyn at 18/02/2014 15:48:31
Hi,

I just saw your message. Our table is at home for veneer repairs, is from 1978 and looks completely original.
I measured the tread of the clamp that is attached to the table itself and concluded that is a regular M8 thread.
Diameter was 7.7mm (thread is a bit worn), and pitch is 8 revs per cm.
I checked with an M8 nut and that fits fine. I also checked the knob with an M8 bolt and that went fine too.

I hope this helps (and is in time).

Brigitte at 25/02/2014 08:30:34
Thanks very much – that’s really helpful. It’ll be so nice not to have our table swivelling about at sea!

JohnF at 25/02/2014 15:20:48
Hi, I’m not sure if I can help – it depends if we’re talking about the same part – I needed to replace two bolts or grub screws low down on the column base to the floor, not the bolt with a plastic knob which tightens the clamp on the column itself. I went through an issue a couple of years ago as the relevant bolts had been lost by a previous owner. in the end confirmed that on mine (built 1977) the threads on the base were indeed imperial, quite unusual and a particularly difficult to obtain now. Today I can’t find the note of what I needed, but in the end found that I could get hold of a couple of grub screws which were actually being sold as spares for a Vincent motorcycle! If this the part you need, I’ll try to find the detail.
It might also be useful to you to know that Toomer & Hayter supply all sorts of bits for tables, pedestals and seats, at http://www.toomerandhayter.co.uk .
Let me know if details of my screws might help.

Brigitte at 25/02/2014 21:00:49
Hi John, thanks for the kind offer and the link.

I do indeed need to make a bolt with associated handle that tightens the upper clamp on the base of the table, not grub screws. The lower, identical clamp is tightened with a piece of polished half inch stainless steel bar, simply formed with a bend and a thread at one end (no plastic)- I have no idea if that is original but I have a lathe and machining something similar isn’t a problem.

Given the continuing uncertainty, I have resigned myself to retrieving the broken part this weekend just to be sure.

JohnF at 26/02/2014 09:59:18
No problem, sorry my grub screw wasn’t relevant – you might in any case find the source useful, it’s the best place I’ve found for really odd imperial nuts & bolts – the Vincent Owners Club Spares Co. at:
https://vocspares.mamutweb.com/
Good luck with the table.

Brigitte at 05/03/2014 18:42:12
Just to say that I’ve confirmed the threads are 8mm metric. In case anyone wanted closure…