Determining Key Size?

[Joe Gargery]

Gentlemen,
I have three clocks that are missing keys and the few keys I do possess do not fit them. The clocks all function fine and keep time well. I've been winding them with different 12 point sockets from my quarter inch drive set. I've checked my Timesavers catalog and, while there are many keys listed, there is no way for me to decide which ones are correct for my clocks.
Rather than just buying keys, willy nilly in hopes of getting the correct size, I finally hit upon the idea that if I posted the movement model numbers here, perhaps the key size can be determined from them? If not, I suppose I could purchase a couple of those star type keys and use those to find the correct sizes.
I would appreciate any help with one or all three of these.
Best, Joe

First one is an Urgos UW 21/26 dated 1973

Second is a Mauthe with no movement number stamped. Clock, I believe, is approximately 80 - 100 years old.

The third is made by Maurer, Pfaff & Maier Clocks with the 3 star mark. I think this one dates 1890's to 1910's.

 

[Willie X]

Well just buy a couple of #8s, a couple of #6s, one #9 and one #10. I would guess this would give you an even shot at it.
Willie X

 

[KurtinSA]

Use a digital caliper and measure the distance across the flats on the arbors. Use that information to discuss with Timesavers which would be the best keys to fit your needs.

Kurt

 

[Bruce Alexander]

If you can get accurate measurements, here's a size chart that may be helpful: Clock key size chart to get the right key
Otherwise I like Willie's trial and error approach. Approximate measurements could get you in the ballpark.

 

[Willie X]

Just go for a dozen. Merritt's minimum order is $25. Buy: 1-11, 1-10, 1-9, 3-8s,
1-7, 3-6s, 1-5, and 1-4. This will cover this time and probably another time, or two.
Willie X

 

[Tim Orr]

Good morning, Joe!

Another way to go is to get one of those 4-pronged or 5-pronged multi-keys ($6 each, or a set for $9), either odd or even sizes. If you find one size is too big and the next one down is too small, you can easily guess that the one you need is the one inbetween. Buy both an odd and even multi, and you can wind your clocks temporarily while you wait for the correct size individual keys to arrive.

Best regards!

Tim Orr