Characteristics of compression springs.

I. Core Functional Features
Resistance and Cushioning: The primary function is to resist axial compressive forces. When subjected to pressure, the spring deforms, converting kinetic or potential energy into stored elastic potential energy, providing cushioning and shock absorption.

Storing Energy: A compressed spring stores elastic potential energy. This property is widely used in applications requiring energy release, such as automatic pens, wind-up toys, and valves.

Providing Pressure: When compressed, a spring exerts opposing forces on both ends. This property is used to maintain close contact between components, such as in clutches, brake systems, and vibrating screens.

II. Structural and Geometric Features
Various Shapes: The most common is cylindrical (consistent pitch), but there are also various shapes, such as conical, olive (with tapering diameters at both ends), and waist drum, to accommodate different spaces and load requirements.

Cylindrical: Provides uniform spring force.

Conical: Provides progressive spring force and, when compressed, allows the spring to completely retract into its own space, saving height.

End Structure: The ends of a compression spring are typically treated differently to ensure uniform and stable force distribution.

Tightened and Ground End: The coils at both ends are tightened and ground flat, allowing the spring to stand upright and maintain a vertical force line. This is the most commonly used method.

Tightened and Unground End: The coils at both ends are tightened but not ground flat. This is slightly less expensive but offers slightly less stability.

Open Untight End: The coils at both ends are not tightened. This is suitable for applications where guidance is not a priority.

Pitch: The distance between coils. Pitch can be uniform or variable. Variable pitch springs can provide nonlinear force variations during compression.

III. Mechanical Properties
Force-Deformation Relationship (Hooke's Law): Within the elastic limit, the compression (deformation) of a spring is proportional to the load (force) it bears. This is the most basic and important mechanical property of a spring. The proportionality coefficient is called the spring stiffness (k), measured in N/mm. The greater the stiffness, the "stiffer" the spring.

High Fatigue Strength: High-quality compression springs must be able to withstand millions or even tens of millions of repeated compression cycles without failure. This places high demands on material selection and manufacturing processes (such as heat treatment and shot peening).

Working Stroke: The maximum distance a spring can be safely compressed. Typically, the design ensures that the spring remains within its elastic deformation range until the spring reaches its solid height (the theoretical height when all coils are in contact).

IV. Material and Process Characteristics
Wide Selection of Materials: Depending on the application, a variety of materials can be used:

High-carbon steel/music wire: Most commonly used, offering high strength and low cost.

Stainless steel: Used in environments requiring corrosion and rust resistance, such as food processing machinery and medical equipment.

Chromium-silicon steel/chrome-vanadium steel: Offers higher fatigue strength and high-temperature resistance, and is used in critical applications such as automotive engine valve springs.

Copper alloys: Such as phosphor bronze and beryllium bronze offer excellent electrical conductivity and corrosion resistance.

Nickel alloys: Used in extremely high-temperature environments.

Mature manufacturing process: Springs are primarily coiled on a spring coiling machine and then tempered to eliminate internal stresses and stabilize dimensions and performance. Surface treatments such as electroplating (zinc, nickel) and painting are used to prevent corrosion.