Compression Springs Manufacturer
are open-coiled helical springs designed to resist a compression force applied along
the axis of the coil. As the coils are compressed from their free length, the spring
operating length is shorten and the compression spring stores energy or provides
a force for the specific application.
are a straight cylindrical spring made of round wire.
Optimum Spring Solutions
in different types and configurations to suit your specifications.
To help you solve basic compression spring design challenges, please visit our
Compression Spring Design Alternatives Guide.
Table of contents:
Common shapes we manufacture are:
- Cylindrical springs, straight or standard: All coils
have the same diameter with a constant rate. These are the most common and cost
effective to manufacture.
- Conical or Tapered: Coil diameter decreases from
one end of the spring to the other. The smaller coils telescope down into the larger
coils as the spring is compressed so that the spring can operate in a smaller axial
space. You can use this type of spring when there is not enough space for a cylindrical
spring. In a conical spring the load vs. deflection curve gets steeper as the spring
is compressed and the larger diameter coils bottom out, reducing solid height.
- Barrel or Convex: Tapered so that coil diameter
at the ends are smaller than the middle coil diameter. These types of spring have
some of the same advantages as conical springs with the added advantage that they
are symmetrical. The reduced end coils help the spring to be centered on a smaller
- Hourglass Springs or Concave: Tapered so that coil
diameter at the ends are larger than the middle coil diameter. These types of spring
have some of the same advantages as conical springs with the added advantage that
they are symmetrical. The enlarged end coils aid the spring to be centered on a
larger diameter hole.
- Variable Pitch: With a varying amount of space between
the coils. This type of
has a non-linear load vs. deflection curve, and is used to minimize resonant surging
and vibration. By adding closed coils in the center of the spring you can reduce
- d (Wire Diameter): Wire diameter for the
- S (Shaft): Maximum diameter of a spring shaft in
- Di (Internal/Inside Diameter): Calculated by subtracting
two times the wire diameter from the external diameter of a spring.
- De (External/Outside Diameter): Calculated by adding
the internal diameter plus two times the wire diameter of a spring.
- H (Hole): Minimum diameter of the hole in which
a spring works.
- L0 (Free Length): Overall length of a spring in
- Number of coils: Total number of coils in a spring.
The above picture shows six coils. To calculate the number of active coils, subtract
two terminating coils from total number of coils.
- P (Pitch): Average distance between two subsequent
active coils of a spring.
- Lc (Bock Length/Solid Length): Length of a spring
when completely compressed.
- Ln (Maximum Loaded length): Maximum permitted length
of a spring after loading. If deflection is higher it may cause plastic deformation.
- R (Spring Rate/Stiffness): the change in load per
unit deflection in pounds per inch (lb/in) or Newtons per millimeter (N/mm).
- L1 & F1 (Length at Force F): Force F1 at Length
L1 can be calculated from equation:
F1 = (L0-L1) * R.
Equation derived from previous for calculating L1:
L1 = L0 - F1/R
- Helix Direction: Right or left-handed. A left-handed
spring loads in a clockwise direction.
- End Treatment: Open, open and ground, closed or
closed and ground ends
with a wire diameter of 0.004" up to 0.120" (0.1mm to 3.0mm)
are the most common
we use to manufacture
You can find other materials and properties listed in the
Round wire is most commonly used for
because it is most adaptable to standard coiler tooling. We can manufacture compression
springs with square, rectangular and special wire sections.
- Operating Environment
- Service Life /Fatigue
are mounted over a rod or fitted inside a hole. When the spring is compressed, it
shortens, pushes back against the load and tries to get back to its original length
thus offering resistance to linear compressing forces.
- Dimensional Limits: As a compression spring assumes
a load and shortens, the body diameter will large. Make sure the wire diameter times
the number of coils is not greater than the space allowed for that spring.
- High Temperature Environment: may affect the length
of the spring. Consider designing your compression spring slightly longer.
- Stress Level: Determined by the dimensional limits
along with the load and deflection requirements. Our
are stress-relieved to eliminate any residual bending stresses produced by manufacturing
process and enhance stress performance of the compression spring.
- Load: Spring Rate multiplied by the deflection from
- Measured Spring Rate: Lbs. of load per inch of deflection.
can be measured by taking the difference in force at 80% maximum deflection and
20% maximum deflection and dividing by the difference in deflection. The spring
rate is constant over the central 60% of the Deflection range. Because of end-coil
effects, the first 20% of deflection range has a considerably lower spring rate.
The final 20% of deflection shows considerably higher spring rate. If possible,
critical loads and rates should be specified within the central 60% deflection range.
- Spring Rate: (R) = Gd4/8nD3
pounds per inch where:
We can manufacture variable rate
to improve performance against buckling and surging, however they are usually more
costly. These springs have a variable body diameter, or a variable pitch. To vary
the spring rate, the amount and rate of active coil stack up is changed throughout
the working range of the spring. As more active coil stacks up, the amount of active
coil remaining active is reduced. This loss of active coil causes the rate to increase.
It is not possible to have a variable rate compression spring where the rate decreases
as the deflection increases.
- R: Rate, pounds of load per inch of deflection
- G: Modulus of rigidity of
pounds per square inch
- D: Wire diameter, inches
- N: Number of active coils
- D: Mean coil diameter, inches
- Deflection: A spring will compress when a load is
applied. It is not advisable to use more than 80% of the maximum possible deflection.
The amount of deflection will be determined by dividing the maximum load by the
- Helix Direction: Consider helix direction when two
or more springs are being nested, or when a spring is mounted over a rod. They must
be alternated to avoid friction between the spring and the rod or coil conflict
between adjacent springs.
- End Treatment
End grinding reduces the solid height of the spring, and will increase the available
load bearing surface of the end coil. Grinding the ends permits greater squareness
control and inhibits buckling. Closed ends prevent tangling. Grinding significantly
increases the spring cost and is often unnecessary for small wire sizes.
- Closed and Ground
- Squared and Ground
We offer fast turnaround on small, medium and large runs. In addition, we welcome
any custom compression spring projects which require limited quantities. Our design
specialists offer you specific advice and design review during the
go into many applications for diverse industries that require high-quality coil
Request For Quote
Are you ready to get started on your spring project? Call our team
for immediate service or complete our Request for Quote Form.