Carnhill 10468 Screw size ?@$%#!

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
I've got an old greenie and the same screws from that work in the Carnhill i got from the group buy. The last number for the code is unclear but it's deff. marked St. Ives 10468
 
The new Carnhills are definitely #4-48. They're not too hard to find, in the Bay Area a good source is Olander in Sunnyvale. Not positive about the original Marinair spec, but M2.5 fine pitch seem to work fine. You won't get a #4-48 into one of the old Marinair holes.
 
Mine may have been butchered or um, re-tapped. I doubt someone would tap a 4-48 thread though.
 
I don't know what the proper screw size is, though I've been told it is an obsolete British standard that is difficult to source. It is VERY close to a 4-40, however, so I bought a 4-40 tap and just re-tap them for my builds.

I've had no problems with this... works great.

JC
 
Thanks, Martin. I believe 6BA is correct. Geoff Tanner told me something like that once. The BA stands for British Ass. Standard... or along those lines. :grin:

Yes, the original thread is obsolete! Let's agree on that.

Weird that Carnhill switched to #4-48 threading...
and weird that some people say the #4-48 works in old original iron but Tim says it doesn't. Can someone test it please? Why would Carnhill switch to #4-48...?

Never heard M2.5 might work, thanks, Tim.

Otherwise we can always do what JC does and tap 4-40...

Whew.
 
Hi Todd,

I'm not sure Carnhill ever switched to 4-48, but have a look at the specs for 4-48 and 6BA:

6BA major diameter 0.1102", pitch 47.9 tpi
4-48 major diameter 0.1120", pitch 48 tpi

perhaps this explains why they're pretty much compatible.

(are we at 3 pages yet? :grin: )

Take care,

M.
 
[quote author="tommypiper"]. The BA stands for British Ass. Standard...[/quote]


...as in what British ASS thought of this as a standard....

-sounds about right :green:
 
[quote author="guavatone"][quote author="tommypiper"]. The BA stands for British Ass. Standard...[/quote]


...as in what British ASS thought of this as a standard....

-sounds about right :green:[/quote]

Exactly. :grin: Just what I was hinting at... Of course CJ provided the answer. 'Twas Mr Whitworth...

Here's actually the link to the BA threads. http://en.wikipedia.org/wiki/British_Association_screw_threads
 
Intresting stuff - thanks! I've used 4-48 on vintage Neve front panels as well, but I bet they were also 6BA to begin with.

EDIT: oops - looks like I've bumped it into a 3-page thread :grin:
 
woo whooo! 3 pages of a thread on threds!

I think tom deserves a prize....
...of course it would be a long screw :green:
 
It's not practical to buy from RS in the states. I think most of us never look for anything at RS. Those in Europe do, but you can already get BA screws via the UK anyway.
 
[quote author="BladeSG"]Anyone try a 2.5mm drill bit and a M3 taper tip tap on these?[/quote]

I just did it without the drill bit (too worried about the softness of brass)..... worked like a new one :thumb:
 

Latest posts

Back
Top