Re: [Harp-L] Reed screws

[Vern <jevern@xxxxxxx>]

It depends on what you mean by "permanently installing the screw or threaded rod". 

 If the screw that you refer to is a flat-head SS screw with its head in a countersink on the back side of the plate (as Farrell did), then there is less chance of stripping the threads when you tighten the nut.  This is true not because of the mechanical arrangement but because the threads are all steel which is much stronger than brass. A disadvantage of using flat-head screws with nuts is that the countersink locates the screw.  If you put the countersink in the wrong place, then the screw is forever in the wrong place too.

If the "threaded rod" that you refer to is screwed into a threaded hole in the plate, then there is just as great a chance of stripping the threads in the hole as you tighten the nut as when you tighten a screw.  This is because the weakest threads most likely to strip are the brass ones in the hole.

Threads strip when they fail in shear as the tension in the shaft becomes too great.  This can occur as you tighten either a screw or a nut.

In any case, stripping of threads is the result of over-tightening the screw or nut.  It is better to gently tighten the screw or nut and then lock it in place with a tiny drop of Loctite or super-glue. If the reed is attached tightly enough so that its base stays in contact with the plate and doesn't rattle…then that is tight enough.

Vern

On Nov 13, 2013, at 9:48 AM, Winslow Yerxa <winslowyerxa@xxxxxxxxx> wrote:

> While screws without nuts are simpler, screws with nuts have an advantage if you replace or reinstall a reed in the same slot more than once. Each time you remove and re-install a screw, you risk stripping the thread cut in the rivet hole in the reedplate. Permanently installing the screw - or threaded rod - and fastening the reed with a nut allows multiple reed installations without stripping the threading in the reedplate hole.
>  
> Winslow Yerxa
> Author, Harmonica For Dummies, ISBN 978-0-470-33729-5
>             Harmonica Basics For Dummies, ASIN B005KIYPFS
>             Blues Harmonica For Dummies, ISBN 978-1-1182-5269-7
> Resident Harmonica Expert, bluesharmonica.com
> Instructor, Jazzschool for Music Study and Performance
> 
> 
> ________________________________
> From: Vern <jevern@xxxxxxx>
> To: daledut <daledut@xxxxxxxxxxxxxxxxxxxx> 
> Cc: harp-l@xxxxxxxxxx 
> Sent: Wednesday, November 13, 2013 9:28 AM
> Subject: Re: [Harp-L] Reed screws
> 
> 
> There is a third option for using screws.  Use 0-80 screws and cut the threads in the plate using a tap.  0-80 screws are easy to find and relatively inexpensive.  Not having to fiddle with nuts is also an advantage.  Using screws in a chromatic is more involved because any screw protrusion on the back side of the plates interferes with the attachment of valves.
> 
> Vern
> 
> 
> 
> On Nov 13, 2013, at 8:03 AM, daledut <daledut@xxxxxxxxxxxxxxxxxxxx> wrote:
> 
>> I saw a video of Brendan Powers replacing reeds on a suzuki harmonica. He was using suzuki self tapping screws. Does anyone know where to get these or similar screws? Also is there a preference of screw and nut over self tapping ? 
>> Dale
>> 
>> 
>> Sent from my Verizon Wireless 4G LTE smartphone