Types of Springs: Definition, Pros, Cons, Mechanical Properties

A spring is a mechanical device that stores and releases energy. Springs can be made from a variety of materials, but most commonly they’re made from hardened steel. A spring is typically formed into the shape of a coil to effectively store and release energy. The most fundamental law relating to springs is Hooke’s Law, which states that the force a spring exerts is proportional to its extension. Spring can be tailored by changing the material or geometry of the spring. This allows engineers to design springs for a wide variety of specific applications.

Types of Springs: Definition, Pros, Cons, Mechanical Properties – CNCJY.com

1. Helical Springs:

Extension Springs

These springs abide by Hooke’s Law, and they have hooks, loops, or other interface geometry at the ends that allow them to be ‘pulled’ and create a resistance force.

-Pros: They store and absorb energy, as well as create a resistance to a pulling force. They’re often used for trampolines, garage doors, and washing devices.
-Cons: They can be dangerous when they fail, as they can cause whiplash or other injuries due to the sudden release of stored energy.
-Price: The price can vary significantly, from less than $1 for small, simple springs, to over $50 for large, custom-made springs.

Torsion Springs

These springs store mechanical energy when they are twisted. When the spring is twisted, it exerts a force in the opposite direction, proportional to the amount it is twisted.

-Pros: They can store a large amount of energy and are commonly used in clothespins, clipboards, swing-down tailgates, and garage doors.
-Cons: They require more material and can be more expensive to manufacture. Their failure can result in sudden, unexpected movement of the attached parts.
-Price: The price can range from $5 for small, simple springs, to over $100 for larger, custom torsion springs.

Compression Springs

These are open-coil helical springs that resist a force applied axially. They are designed to oppose compression and return to their uncompressed length when the applied force is removed.

-Pros: They are one of the most efficient ways to store energy and can be used in a wide variety of applications, including automotive suspension systems, medical devices, and electronics.
-Cons: They can buckle under certain conditions, and their efficiency can decrease over time due to wear and tear.
-Price: The price can range from $1 for small, simple springs, to over $50 for larger, custom compression springs.

Spiral Springs

These are made from a flat strip of metal that is wound into a spiral. They are used in clocks, watches, and other devices that require a constant force.

-Pros: They provide a constant force over a large range of motion, which is useful in applications like clocks and seatbelts.
-Cons: Their performance can degrade over time if they are not properly maintained.
-Price: The price can range from $10 for small, simple springs, to over $100 for larger, custom spiral springs.

2. Leaf Springs:

Elliptical Leaf Spring

These are also known as “full elliptical” springs because they form a complete ellipse. They’re comprised of a central leaf (or main leaf) that has eyes at both ends and additional leaves of decreasing length.

-Pros: They provide a soft, smooth ride and are durable.
-Cons: They are large and heavy, which can decrease fuel efficiency.
-Price: Depending on the size and material, they can range from $100 to $400.

Semi-Elliptical Leaf Spring

These are the most common types of leaf springs and are essentially cut-in-half elliptical leaf springs with one end attached to the vehicle’s frame.

-Pros: They are simpler and lighter than full elliptical springs.
-Cons: They provide a harsher ride compared to full elliptical springs.
-Price: They typically cost between $50 and $200.

Quarter Elliptical Leaf Spring

These are further modifications of the semi-elliptical leaf spring where only a quarter of an elliptical spring is used.

-Pros: They are light and compact.
-Cons: They have a lower load capacity compared to full and semi-elliptical springs.
-Price: They typically cost between $50 and $200.

Three-Quarter Elliptical Leaf Spring

These are a compromise between semi-elliptical and quarter elliptical leaf springs.

-Pros: They offer a balance between weight, load capacity, and ride comfort.
-Cons: They are more complex and more expensive to manufacture.
-Price: They typically cost between $100 and $300.

Transverse Leaf Spring

These are mounted transversely (across) rather than longitudinally (along the length) of the vehicle.

-Pros: They allow for a lower vehicle height and are lighter in weight.
-Cons: They provide less lateral stability.
-Price: They typically cost between $100 and $300.

3. Disk Springs:

Belleville Disk Spring

This is a conical shell that can be loaded along its axis either statically or dynamically.

-Pros: They have a high load capacity and can be used to dampen vibration and provide a constant load or resist shock impact. They are also useful in applications with space constraints.
-Cons: They require precise control over their manufacturing process to ensure consistent performance. They also require a higher upfront cost for tooling.
-Price: They typically cost between $1 and $20 depending on size, quantity, and specific design considerations.

Curved Disk Spring

These springs are curved and can handle larger loads. They’re often used in applications that require a low spring rate and large deflections.

-Pros: They can handle larger loads and have a larger deflection compared to other disk springs.
-Cons: They can deform under excessive loads and may not return to their original state.
-Price: They typically cost between $2 and $25 depending on size, quantity, and specific design considerations.

Slotted Disk Spring

These springs have a slot cut out from their periphery towards the center, allowing them to resist bending stresses.

-Pros: They offer high resistance to bending stresses and are able to handle larger loads.
-Cons: They have a limited deflection range and require precision in manufacturing.
-Price: They typically cost between $5 and $30 depending on size, quantity, and specific design considerations.

Wave Disc Spring

These are pre-stressed flat washers that produce a relatively light load for a small deflection.

-Pros: They offer light loads, can accommodate larger deflections, and can be used in applications with space constraints.
-Cons: They have a lower load capacity compared to other types of disk springs and may not be suitable for high-load applications.
-Price: They typically cost between $0.50 and $15 depending on size, quantity, and specific design considerations.

Spring Type	Material	Wire Diameter (in)	Coil Diameter (in)	Free Length (in)	Spring Rate (lbs/in)	Maximum Deflection (in)
Compression	Music Wire Steel	0.060	0.500	1.000	30.0	0.500
Extension	Beryllium Copper	0.032	0.250	1.250	12.5	0.750
Torsion	Music Wire Steel	0.032	N/A	1.500	5.0	45 degrees
Constant Force	Phosphor Bronze	0.040	0.375	1.250	Gradual 5-15	1.000
Push/Pull	Spring Steel	0.125	0.750	2.000	50.0	0.500
Volute	Stainless Steel	N/A	1.250	3.000	100.0	0.750

Mechanical Properties of Some Spring Wires