Different Types of Compression Springs and Their Applications

Springs are simple mechanical tools used to store energy for specific applications. Some common examples include the tension springs that pull a fence gate closed, torsion springs on the lid of a box, and extension springs that counterbalance the weight of a garage door. Another type is compression springs, which we’ll explore here.

Compression Springs Explained

Depending how they are wound, shaped, and the materials used, springs accomplish different tasks. Compression springs are used in applications that call for moving or keeping two components apart, such as between die plates in a stamping press, between a door and the wall, or the springs in a mattress and box spring set.

The wire loops in a compression spring are spread apart to some degree when the spring is not under any force – this is called the pitch between the coils. As force is applied to the ends of the spring it becomes compressed and the wire loops move closer together and may even touch. This is how the spring stores energy that, when the external force is removed or decreased, pushes or holds things apart. The movement of a spring when force is applied or removed is called deflection.

Different Types of Compression Springs

Compression springs are usually made from metal wire that is coiled into a helix. High carbon steel and stainless steel, and alloys of steel, copper, and nickel are the most common materials for springs; although, polymer resin composites can also be used. The cross section of the wire can be round, trapezoidal, square, or wide and flat. Various gauges of wire allow for different amounts of stored and exerted force as well as the spring’s size and durability in use. Springs can be manufactured in many shapes, diameters, and lengths. Wire ends can be cut square, ground, or otherwise shaped depending on the application.

While they can be highly customized for specialized uses, compression springs generally come in these four shapes:

• Straight or cylindrical. This is the most common shape for compression springs. They have a uniform diameter from end to end.
• Convex or barrel-shaped. These springs are widest in the middle with tapered ends, similar to the shape of a barrel. This shape is less prone to buckling than a straight cylinder.
• Conical or tapered. These cone-shaped springs are tapered on one end. This shape gives a telescoping effect where the coils can collapse into a flat disk, which saves space under maximum deflection.
• Concave or hourglass. These springs are narrowest in the middle with wider ends. They can be less prone to buckling than other shapes.

Applications for Compression Springs

Compression springs are used in many industries, operations, and products. Their ability to store and exert force makes them a good choice to move components or keep them in place, to ensure proper alignment of parts, or to reduce vibration and excessive motion. Some uses for compression springs include:

• Industrial machinery. Compression springs are used in various industrial machines such as stamping presses, CNC machines, and packaging equipment. Springs help control force, absorb vibrations, and maintain proper alignment of components. 
• Metal stamping and forming. In metal stamping, special heavy duty compression springs called die springs are used to position and hold sheet metal. They can also be used to create return pressure for die strippers to remove tooling from the workpiece as the press opens . 
• Injection molding. Compression springs are often used in injection molding equipment to ensure proper retraction of ejector plates.
• Assembly operations. In automated assembly operations compression springs may be used for motion control as actuators and in conveyance equipment. They can also be used in specialized tooling and equipment to position or reset components between cycles. 
• Automotive components. Compression springs are used throughout cars, trucks, and other vehicles including engine systems, suspension systems, seats, and pedals. 
• Electronics components. Battery compartments, push buttons, and motors in electronic devices like cell phones all use compression springs. 
• Appliance and household item components. Compression springs are found in appliances such as washing machines, air conditioners, and refrigerators. They are also used in smaller items like light switches, door locks, staplers, and retractable pens.
• Medical device components. Medical devices use small compression springs for many applications including valves and pumps, implantable devices for widening arteries, inhalers, pill dispensers, and auto-injection syringes. Compression springs are also used in large medical equipment such as overhead lights with articulated arms, adjustable beds and tables, monitoring equipment, and imaging machines. 
• Hand tool components. Compression springs are used in various hand tools including caulk and adhesive guns, spring-loaded wire or metal snips, wire strippers, clamps, hanging scales, and hand-held compressor tools.

Compression Springs from Ready Technology

Ready Technology is an industry leader in metal coil and nitrogen gas springs for metal stamping and forming applications. Our SuperSprings line of compression die springs is available in four color-coded load classifications (in accordance with ISO 10243). Uniform lengths and diameters provide full interchangeability between load ratings. Spring diameters are guaranteed to fit in the holes and over the rod diameters listed in the dimensional data.

Learn more about SuperSprings here or contact us today for a free quote

How Do Gas Springs Work?

Nitrogen gas springs, a type of hydraulic gas springs, are a popular alternative to traditional mechanical springs. They come in a variety of sizes, generate consistent and powerful forces, and are very durable. This article explains how they work, some of their benefits, ways to configure them, and how they are used in metal stamping and metal forming across industries.

What is a Gas Spring?

Like mechanical springs (i.e., metal coil springs), gas springs are used inside dies for metal stamping and metal forming applications with a press. The difference is instead of storing potential energy in a metal coil, nitrogen springs use pressurized nitrogen gas.

Because the gas spring mechanism operates based on the pressure of gas inside the spring housing, it is able to apply an immediate, constant force from initial contact to final stroke. A gas spring’s force is measured in decanewtons (daN).

Ready’s Design-Tite springs come in a variety of lengths and diameters as well as motion control springs that can be paused at a desired working position.

When properly installed, nitrogen gas springs are extremely safe and last for millions of cycles. All of Ready Technology’s Design-Tite nitrogen gas springs come with comprehensive, illustrated safety and installation instructions.

How Do Gas Springs Work?

Gas springs consist of a cylindrical metal housing and snug-fitting inner piston. While they are manufactured in a range of lengths and diameters, the stroke length is the critical measurement for determining both piston length and the corresponding housing type. Shorter pistons use one-piece housings, which are bore-sealed. Longer pistons require a two-piece housing. Ready’s two-piece housings are specially sealed with an end cap that is both threaded and welded for added durability and safety.

The nitrogen is tightly sealed in the housing, allowing the gas to compress and store energy when force is applied to the piston, pushing it down. When force is removed from the piston, the pressure is released and the piston is pushed back up by the expanding gas. A small amount of lubricating oil is also sealed inside the spring housing to keep the piston moving smoothly in both directions.

One gas spring can replace up to 10 traditional mechanical springs, even though gas springs are much more compact in size. When fully charged the force remains smooth and consistent from initial contact to final stroke, which gives great control over the metal forming process.

What Are the Benefits of Gas Springs?

Nitrogen gas springs offer many benefits over mechanical springs, including:

• Immediate, consistent force
• Durability and reliability because less prone to wear and tear than coils
• Rechargeability
• Compact for use with short stroke lengths or shut heights
• Expandable by connecting multiple springs to operate in unison and increase force
• Adjustable pressure for precise operation and control over the stamping process

What Are the Different Types of Gas Springs?

Gas springs can be used singly or in groups. By connecting multiple springs it’s possible to combine their force and evenly distribute it throughout the die. Configurations fall into three categories:

• Autonomous Gas Springs
  Single, closed spring consisting of cylinder and piston, operated individually.
• Interconnected Gas Springs
  Multiple single springs can be connected with flexible hoses to vary the amount of force produced for different applications. Care must be taken to avoid twisting the hose or making sharp bends in it, which can impede the flow of gas between springs.
• Compact Manifold Gas Springs
  Another way to connect multiple gas springs is with a manifold. This is a metal plate with openings for threaded springs to screw into. Channels are drilled inside the manifold block to connect the springs so they operate as a single unit, exerting greater force that is also evenly distributed throughout the die. Manifolds include a control panel with a gauge and valves to fill or discharge nitrogen.

What Industries Use Gas Springs?

Almost anywhere that a coil spring is used in a press a gas spring can be substituted. One gas spring can replace multiple mechanical springs, and it’s easy to adjust the gas pressure to fine tune the force for precision applications. What’s more, because they are generally compact, nitrogen gas springs are well suited to applications with limited space in dies.
All of these features make gas springs a solid and reliable choice in many of the industries that stamp parts and utilize other metal forming processes including the automotive (both OEM and aftermarket), aerospace, appliance, office and home furnishing, and HVAC industries.

How can you Select the Best Gas Springs for Your Needs?

As always, the details of your application determine the equipment you need. When selecting gas springs, start by determining your needs for force in daN, stroke length, shut height, piston and cylinder diameter, and number of springs.

Not sure how to get started? Deciding between multiple options? Whether you are replacing existing coil springs or designing a new die set for a stamping application, the Ready Technology team has the engineering expertise to help you find the right spring and accessories.

At Ready we have many nitrogen gas spring options available and in stock, along with flanges, valves, gauges, manifolds, hoses, and all the accessories you need. Contact us today!