Mainspring selection

[Bethan36]

Hi there.

 

I have acquired an assortment of new mainsprings, however, neither are in marked envelopes, they are just held in the plastic ring, some have a number like '80' on the plastic and others don't.  So my question is how I identify these mainsprings?

I have attached a phot to show how they have been delivered.

 

Thanks in Advance.  Bethan

 

[oldhippy]

Unless you know the make of the springs those numbers could mean anything. The only way in finding out the height and strength will be to remove them from the rings and measure them.

[praezis]

Even easyer: all you need is a calliper.

1. measure the diameter in the ring (is the number in 1/10 mm)
2. measure the hight
3. measure the blade thickness: thickness of the packed blades on one side divided by the number of coils.

Your spring is determined.

If you want to know which movements they fit in, you need e.g. the GR catalog (available online at Cousins afaik).

Frank

[Nucejoe]

33 minutes ago, praezis said:

Even easyer: all you need is a calliper.

1. measure the diameter in the ring (is the number in 1/10 mm)
2. measure the hight
3. measure the blade thickness: thickness of the packed blades on one side divided by the number of coils.

Your spring is determined.

If you want to know which movements they fit in, you need e.g. the GR catalog (available online at Cousins afaik).

Frank

You may never find producers spec, yet can use it.

Insert barrel arbor as the coil is in the ring, should hold tight. The coil inside the ring should look about the same  as the old one inside the barrel. Take into account all said above.  Best wishes.