Old Broken OM bellows wanted...

[lauriek]

What I really need is one little screw - the one which holds the bellows to the front standard. Does anyone have one of these screws spare, or alternatively know the specifications of the screw? Cheers!

[ChrisR]

Do you mean one of the 4 which go through a thin plate with a big hole in the middle?
You could invest in a whole box of watchmakers screws, something like
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0627387606

The threads aren't actually critical. If they're tight they go in and stay in just fine!

[rjlittlefield]

or alternatively know the specifications of the screw?

I just measured one. It's a small but standard metric thread: 2.50 mm outside diameter x 0.45 mm pitch.

--Rik

[Mitch640]

Rik, I'm interested in how you measured it?

[rjlittlefield]

Digital caliper. The thread pitch was a bit troublesome because my metric thread gauge only goes down to 0.5 mm. So I resorted to measuring 4.5 mm for 10 turns, viewing under a stereo dissecting scope at 10X or so. After that, some reassurance was provided by http://en.wikipedia.org/wiki/ISO_metric_screw_thread, which tells me that 2.5 mm diameter x 0.45 mm pitch is indeed a standard metric "coarse" thread.

--Rik

[xys]

Also, Small Parts might be a good source, e.g. this is a pack of 100 16-mm long steel screws, M2.5-0.45 for about $5:

http://www.smallparts.com/dp/B000NHSAIO ... p_g2c_asin

(they have also other materials, e.g., nylon, etc.)

Rashid