channel springs id

Question

I ordered some spings a little while ago. Perfect fit. I am struggling to find a match for these though. The channel (metal) is 18" they don't look to have shoes on the plastic clips but not positive. They have been broken for some time. Very brittle. The tope slides into a tab clip. They are all still there and good.

Not sure about the black plastic piece shown in spring 4? If it's needed or not. It looks like it keeps the spring from going to far up and away from the tab clip?

Numbers on the spring are 1720C.

I will need a dozen of them.

Thank you

Casey · Accepted Answer

Hello,

It looks like you have either our S351-18, with a 15-002 bottom attachment, or S390-18, with a 15-001 bottom attachment. Take a look at the image below to determine which balance you'll need. You'll also need a 1720 spring strength option for your replacement balances.

I don't recognize the black part in your photo but if you could show us a photo of an undamaged one still installed, that might give us an idea of what you need. Thank you!

Comparison of the S351 and S390 balance shoes.