Help needed - HMV 23 / Columbia 24 Soundbox Thumbscrew

[chrissydretro]

Hi All,

I was wondering if someone could help me find the correct BA Thread measurements for a needle thumbscrew for the HMV 23 / Columbia 24 soundbox. I have attached a copy of the BA Thread measurements and the soundbox for reference.


Appreciate your help and support.

Thanks in advance,
Chris

[soundgen]

It isn't as easy as that ! HMV always used UNC and UNF threads as a leftover thing from Victor manufacturing , this is quite useful sometimes say if you need bolts to hold a gem base onto the case ,UK Columbia always use BA threads but which was used after they merged to form EMI I don't actually know , they seem to pick and mix lots of things when EMI

[chrissydretro]

Hi Soundgen,

Thanks for your reply. Im a little confused with your message. I just need the standard BA Thread size for this specific no 24 soundbox thumbscrew.

This is a standard measurement irrespective of the 1931 Merger where Columbia Graphophone in the UK merged with the Gramophone Company (which sold records under the HMV label) to form EMI.

Hope someone can help.
Thanks Chris

[soundgen]

Hi Soundgen,

Thanks for your reply. Im a little confused with your message. I just need the standard BA Thread size for this specific no 24 soundbox thumbscrew.

This is a standard measurement irrespective of the 1931 Merger where Columbia Graphophone in the UK merged with the Gramophone Company (which sold records under the HMV label) to form EMI.

Hope someone can help.
Thanks Chris

The point is it could be a BA thread but might be a UNF thread , I'll try and see if I have a soundbox to try one . i take it you need a needle screw or is this just academic ?

[JerryVan]

Hi Soundgen,

Thanks for your reply. Im a little confused with your message. I just need the standard BA Thread size for this specific no 24 soundbox thumbscrew.

This is a standard measurement irrespective of the 1931 Merger where Columbia Graphophone in the UK merged with the Gramophone Company (which sold records under the HMV label) to form EMI.

Hope someone can help.
Thanks Chris

The point is it could be a BA thread but might be a USF thread , I'll try and see if I have a soundbox to try one . i take it you need a needle screw or is this just academic ?

What he's saying, is that it might not be a metric, (BA), thread. If not, it's likely something like a 1-56UNF, 1-72UNF, or 2-56UNF thread, (all of which Victor used at various times).

[chrissydretro]

Hi Soundgen,

Apologies for the delayed response - I was unable to login after forgetting my password Yes the info is for a replacement thumbscrew.

A guy who might have a spare one asked me for this info. I thought this forum would be a great reference point.


Kind Regards,
Chris

[chrissydretro]

Hi JerryVan,

No worries thanks for clarifying.


Kind Regards,
Chris

[soundgen]

i found this Columbia 20 soundbox ( looks like yours slightly different mask ) and measured the screw and it is 0.089 " so I guess it is 8 BA , it looks like 8 BA to me I used tio have lots of 8 BA needle screws and used them on broken off screws after retapping

[chrissydretro]

Thanks for this soundgen - Much appreciated

Chris