Hole
Diameter: This identifies the outside diameter (OD) of
the die spring. Raymond die springs are available
in eight different hole sizes matched to standard drill
sizes. Each spring is made to fit in the hole, so the OD
of the spring is actually less than the hole diameter.
Rod Diameter: This is a nominal identification of the
inside diameter (ID) of the die spring. Raymond
die springs are available in eight different hole sizes
matched to standard stripper bolts. Each spring is made
to fit over the rod, so the ID spring is actually
greater that the rod diameter.
Free Length: The Length of a die spring before it is
subject to any operating force or load.
Preload: The distance the free length of the die spring
is reduced by the pressure of the assembled tool.
Operating Travel: The distance which is subtracted from
the spring length after operating force has been
applied.
Deflection: The amount of change in spring length when
force is applied.
Compressed Length: The length of the spring after
operating force has been applied. The compressed length
is computed by subtracting the initial compression and
the operating travel from the free length.
Solid Height: The length of a spring when it is
compressed by enough load to bring all the coils in
contact with each other.
Remove Set: The manufacturing process of closing a
compression spring to solid to eliminate load loss in
operation.
Permanent Set: This happens when the elastic limits are
exceeded and the spring does not return to its original
length when the load is released.
Elastic Limit: The maximum compression stress that a die
spring can endure without taking permanent set.
Load: This is the force built up by compressing the
spring. Load is expressed in terms of total pounds,
which is the load on the spring per a specific unit of
deflection. Load is also directly related to stress. As
the spring is compressed, load is generated and stress
on the coil increases.
Stress: In a spring, this describes the internal force
that resists deflection under load. This force is equal
to, and in the opposite direction of, the external load.
Stress is expressed in thousands of pounds per square
inch of sectional area.
Hole
Diameter: This identifies the outside diameter (OD) of
the die spring. Raymond die springs are available
in eight different hole sizes matched to standard drill
sizes. Each spring is made to fit in the hole, so the OD
of the spring is actually less than the hole diameter.