I am rebuilding a Hampden William McKinley 16 size, serial number 3519986. My questions are, what is this spring called, is it broken? If so, what is it supposed to look like, and does anyone have an extra? Thanks

I don't know what others call them, but I call it the set lever spring.

And, yes - it's broken!

You can make one if you find a suitable piece of steel wire and bend it carefully. It shouldn't be too thick or too thin (measure the original to get the gauge). Soften the wire by heating it and allowing it to cool slowly, then bend it to shape and harden & temper it.

If you leave it too hard, it will break. If you leave it too soft, it will bend. Play around with an unformed piece of the wire until you get it to be a spring, then heat treat the piece you bent to shape the same way (if you experiment on the shaped piece, you'll get a lot of practice shaping springs ).

Thanks. Does a special pair of pliers help? Where can I purchase the spring wire?

quote:

If anyone would be willing to form a quantity of these for some of the more difficut to find applications there is a market for them.

True! I can't understand why someone isn't turning these out in quantity. Of all watch parts, it would seem that these would be the easiest to produce. I would think that once you set-up the jigs (or whatever) and bought a spool of spring-wire, your cost would be pennies. I'd buy a dozen 18sz Hamilton's for a couple bucks each.

Thanks to you all for responding to this post. I measured the broken spring and it is 0.2 mm by 0.6 mm (rectangular). I called several places today and inquired about spring wire. All I found was circular. Do I use a size of similar cross-sectional area?

It looks like both springs are broken.The Shipper, and the Yoke spring


Frank