[pianotech] Brass Rail

[Roger Gable]

Ron,
 I don't see any standard that used 52 threads per inch. My thread gauge 
tags it at 56, but we could be measuring two different manufacturers, or my 
eyes are getting worse than I'd like to admit.
On a related subject. I got involved in thread technology about a month ago 
when I couldn't gauge the threads of the Samick leg and lyre bolts. I 
discovered that the threads used by Samick is an obscure thread called 
British Whitmore. So if you loose the leg or lyre bolts to these pianos, 
your only replacement source is from Samick.
Roger Gable

----- Original Message ----- 
From: "Ron Nossaman" <rnossaman at cox.net>
To: <pianotech at ptg.org>
Sent: Sunday, September 19, 2010 2:54 PM
Subject: Re: [pianotech] Brass Rail


> On 9/19/2010 3:49 PM, John Ross wrote:
>> Thank you very much, Roger.
>> Your letter explains the dilemma, with apparently no real fix, other than 
>> do the best you can.
>> APSCO was where I used to get the exact replacements.
>> Tuner's Supply also supplied the correct ones.
>> 3-48 is a size that Micro Mark carries, so I guess that will be the 
>> closest.
>> I seem to remember that Mr Schandler (sp) of APSCO continued selling 
>> screws after Schaff bought him out.
>> Does anyone know if he still does?
>> John Ross
>
> Hi John,
> Yep, I looked at the wrong line. Screwed up, sorry. It is indeed a #3, but 
> it's neither 48, nor 56 threads per inch. My 26 tpi gauge neatly and 
> precisely fits every other thread, which makes it 52tpi. At least that's 
> what my jar full of leftovers are.
>
> That makes the closest match M3 x .5, which is 0.020" (0.5mm) bigger than 
> the original, at about 50.8 tpi, and there are both screws and taps 
> available in this size.
>
> Ron N
>