There are several options available for the delivery of spiral springs. They are shipped with or without assembly aids such as retaining rings or, depending on their use, also as an assembly.
As a rule, the outside diameter of spiral springs in the untensioned state is adapted to the installation conditions.
These springs can therefore be installed without assembly aids. The outer diameter of these springs matches the inner diameter of the housing.
The spring characteristic curve is linear.
Some springs also have a non-linear characteristic curve.
Their outer diameter is larger than the space available for installation.
These springs are either pretensioned, fixed and inserted into the housing during assembly or they are wound into retaining rings for transport. Retaining rings of this kind are often used as an aid in the manufacture of spiral springs. Because they are not removed until installation, they also serve as an important assembly aid.
Depending on the application, spiral springs can also be supplied as an assembly.
So-called “rollers” are used here as centering aids. This centering aid can be riveted, glued or laser-welded to the spiral spring . It is used for example to fix the watch spring to the balance staff in the watch mechanism.