My question is, are the case screws indigenous to the movement size,as pertains to thread count,length,and shank size. And can they be interchanged between different watch companies,given the movement sizes are the same.

Frank Juchniewicz

Frank,
The short answer to your question is "sometimes".
There can be a couple of different thread and shank diameters used by American manufacturers for a given size, but some case screws are interchangable between a couple of different manufacturers. Since the thickness of different maker movements for the same size have to be about the same to fit in standard size cases, length is usually not a problem.
Remember though, that there are always exceptions, so try everything gently, don't force, and make sure that the end of your case screw doesn't start hitting the underside of the dial, which could crack it.
BTW, Case screws from European makers usually won't fit American movements, they use a different thread pitch.

Ed Ueberall
NAWCC 49688
IHC Member 34
The Escapement

Ed

Thanks for the information. I was worried about the thread pitch, as I would not want to cross-thread, and end up with a problem that wasn't there before.

Frank Juchniewicz

Frank,

I recently serviced an Illinois 12s. It was missing a case screw. Amazingly, an 0s Elgin case screw fit perfectly. Although I did have to shorten it! Go figure.

John D. Duvall
Vice President, Education

John

I just got back home,been Deer hunting in Western Maryland. While I was out there I ran across a fellow who was in the Antique buisness, turns out that he had a whole cigarbox full of movements, and parts of movements. He had no use for them, so he gave them to me.I haven't gone thru the box yet,but I may get lucky and find that elusive screw I need. And who knows what else.

Frank

Frank Juchniewicz

Frank,

Do you have any information on the movement that is in need of a case screw? I'm sure someone in our community has what you need.

Congrats on the cigar box full of parts. You can never have too many spare parts!

John D. Duvall
Vice President, Education

Hi John

This is what info I have on the movement.
Elgin-#3,687,602
18s,f.pl.,grade 96,model 2,L.S.,S.W.,and Gilded. The screw missing is a flat head,I measured the length at 7.11mmX 1.15mm diameter,and it is threaded halfway up the screw.
I have no way of measuring thread size. Hope this helps.

Frank

Frank Juchniewicz

Frank,

Let me check with Santa later tonight.

John D. Duvall
Vice President, Education

John

Thank you for sending along that case screw,it worked fine. It was nice talking to you on the phone.Have been able to salvage a couple of movements from that cigar box,about seven. There where no rare ones found,but what I did find will keep me occupied thru the winter months.


Frank

Frank Juchniewicz