Conical compression
springs

Helical springs whose diameter tapers progressively from the base to the tip. They deliver maximum lateral stability, a minimal solid height through telescoping, and a progressive spring rate.

The ideal choice when stability and compressed length are critical: long travel with a minimal solid height, resisting buckling thanks to their wide base.

Technical enquiry
Conical compression spring
Conical steel compression spring, with the coil diameter tapering from the wide base to the tip
Solid height
~1–2 wire Ø (telescoping)
Stability
Lateral · no guide rod
Spring rate
Progressive (non-linear)
Material
Steel · stainless · alloys
01

What are conical compression springs?

Conical compression springs, known internationally as conical springs, tapered compression springs or cone springs, are helical springs in which the coil diameter tapers progressively from a wide base to a narrower tip. Like any compression spring, they work by opposing an axial load, but their conical geometry gives them properties a cylindrical spring does not have.

They are the ideal choice when stability and compressed length are critical: they deliver long travel with a minimal solid height and resist buckling thanks to their wide base, in many cases eliminating the need for a guide rod or tube.

This page is a specialised variant of compression springs: it focuses on what is unique to the conical profile —telescoping, stability by geometry and a progressive spring rate—.

02

The telescoping effect and solid height

The most distinctive advantage of the conical spring is its reduced solid height.

Since each coil has a slightly smaller diameter than the next, when compressed the coils nest inside one another (telescoping) instead of stacking up. The result is a compressed height of approximately 1 to 2 wire diameters, versus the sum of all the coils in an equivalent cylindrical spring.

This is decisive in applications where the available axial space at the end of travel is minimal but a long travel or high loads are required. To achieve full telescoping, the coil diameters must be sized so that no coil binds against the adjacent one before nesting.

Key point

Versus the solid height of a cylindrical spring (sum of coils · n · d), the conical spring compresses down to almost the thickness of a single coil.

FIG · telescoping effect

The conical spring in the free and compressed positions: the smaller-diameter coils nest inside the larger-diameter ones down to a solid height of ~1–2 wire diameters.

03

Lateral stability and buckling resistance

FIG · buckling · cylindrical vs. conical

At the same free height, the slender cylindrical spring buckles sideways under load; the conical spring stays stable, seated on its wide base.

A cylindrical compression spring tends to buckle (deflect sideways) when its free length exceeds about 4 times its diameter (high slenderness ratio). The conical spring solves this problem through its geometry:

  • Wide baseProvides a stable seat that dramatically reduces the tendency to buckle.
  • High slendernessAdds stability to assemblies with a high slenderness ratio where a straight spring would deform.
  • No guideIn many designs it eliminates the need for a guide rod or tube, simplifying the assembly.

In addition, the conical spring reduces resonance and vibration (surge): with its variable pitch, the natural period of vibration changes as the coils bottom out, instead of staying constant as in a cylindrical spring.

Shall we talk about your project?

Tell us the load, travel, target solid height and degree of taper — and we'll get back to you with the optimal conical compression spring. Free engineering support, manufacturer since 1974.

Contact the engineering team
04

Progressive (non-linear) spring rate

Unlike the cylindrical spring —with a practically constant spring rate—, the conical spring has a progressive (non-linear) spring rate. The reason is geometric: a smaller-diameter coil generates more force than a larger-diameter one, and since the conical spring combines different diameters along its body, the load-deflection curve is not a straight line.

The typical behaviour is: as it compresses, the larger-diameter coils (softer) bottom out first, leaving only the smaller-diameter ones (stiffer) active. The spring becomes stiffer as it compresses —soft at the start of travel, firm at the end—. By adjusting the degree of taper and the pitch this progression can be tuned, and even variable-pitch variants can be designed that maintain an almost constant spring rate despite the conical shape.

Design note

Because the spring rate is variable, the spring rate value shown in the catalogue for a conical spring is an estimated average, not a constant. For a specific working point it is best to calculate the force at that particular deflection with the engineering team.

FIG · load-deflection curve

The cylindrical spring follows a straight line (constant spring rate); the conical one describes a progressive curve: soft at the start of travel and firm at the end.

05

Coiling direction

The coiling direction of standard conical compression springs is generally right-hand, but no specific direction is defined: the force and the operation are not affected by the direction of coiling.

Depending on production, the parts can be made with right-hand or left-hand coiling interchangeably. The direction is only specified when the application requires it —for example, springs that work nested one inside another or threaded onto a component—.

06

Materials

Conical compression springs are manufactured in the same range of materials as cylindrical ones, selected according to load, environment and cycles.

Material range
MaterialDesignationApplication
Music wireASTM A228High strength · dry environments
Oil-tempered steelASTM A229Medium and dynamic loads
Chrome-silicon steelASTM A401High stress, temperature and shock
Stainless steel 302 / 316 / 17-7 PH—Corrosion · marine environments · food
Phosphor bronze / beryllium copper—Electrical conductivity

For high temperature, stainless steels (302 / 316 / 17-7 PH) and special alloys are selected on request. The engineering team recommends the material according to the specification.

07

Industrial applications

Conical springs are chosen whenever stability, low solid height or a progressive load response is the priority.

01Battery contacts · low profile

Minimal compressed height

Low-profile assemblies where the axial space at the end of travel is minimal but a long travel is required: battery contacts, push buttons.

02High-slenderness areas

High-slenderness assemblies

Replaces slender cylindrical springs that would buckle and eliminates the guide rod or tube, simplifying the assembly.

03Shock and impact

Shock and impact absorption

The wide base provides a stable seat and the progression cushions the impact: soft at the start, firm at the end.

04Compressors · valves

Compressors and valves

Lateral stability under high, repeated loads. The variable pitch reduces resonance (surge).

05Soft → firm feel

Progressive load response

Mechanisms with a soft feel at the start and firm at the end: the large coils bottom out first and leave the stiff ones active.

06On request · engineering

Custom manufacturing

Sizing of load, travel, solid height, taper and material. Specialist manufacturer since 1974.

08

Frequently asked questions

01 What advantages does a conical spring have over a cylindrical compression spring?

Three main ones: greater lateral stability (it resists buckling thanks to its wide base, often without the need for a guide rod), a much lower solid height (the coils nest or telescope, compressing down to 1-2 wire diameters) and a progressive, non-linear spring rate (soft at the start, firm at the end). It is chosen when stability and a short compressed length are critical, or when a progressive load response is needed.

02 What is the telescoping effect of a conical spring?

It is the ability of the smaller-diameter coils to nest inside the larger-diameter ones when compressed, instead of stacking one on top of another. Thanks to this, the solid height can be reduced to approximately 1 or 2 times the wire diameter, versus the sum of all the coils in a cylindrical spring. To achieve it, the diameters must be sized so that the coils do not bind against each other before nesting. It is the key advantage in applications with very limited axial space.

03 Why does a conical spring have a variable spring rate?

Because its force depends on the coil diameter: a smaller-diameter coil generates more force than a larger-diameter one. Since the conical spring combines different diameters along its body, the load-deflection curve is not linear. As it compresses, the large coils (softer) bottom out first and the small ones (stiffer) remain active, so the spring becomes progressively stiffer. The catalogue spring rate is therefore an estimated average, not a constant.

04 Does a conical spring need a guide rod?

In many cases no. Its wide base gives it lateral stability far superior to that of a slender cylindrical spring, reducing or eliminating the tendency to buckle without the need to guide it on a rod or inside a tube. This simplifies the assembly. In a cylindrical spring, by contrast, buckling appears when the free length exceeds about 4 times the diameter and usually requires a guide.

05 Does the coiling direction matter in a conical compression spring?

No, except in specific cases. The standard direction is usually right-hand, but the force and the operation do not depend on the direction of coiling, so standard conical springs are not defined with a specific direction and are made right-hand or left-hand depending on production. It is only specified when the application demands it, for example in springs that work nested one inside another.

Do you need stability and a minimal solid height?

Send us the load, travel, target solid height, degree of taper and service environment — and we'll respond with the optimal conical compression spring, standard or custom. Free engineering support, manufacturer since 1974.

Technical enquiry