Spring Work's Blog

Coil Springs

Spring Works — Fri, 11 Jan 2008 22:26:25 +0000

Introduction to Coil Springs
A Coil Spring is a mechanical device that has the shape of a Helix (Spiral). Coils are manufactured utilizing high content carbon metals. These types of metals have elastic properties which when heat treated and are conducive to coil spring function. There are three basic types of coil springs used in 3 main industries. The 3 types of coil spring are: Compression, Extension, and Torsion. The 3 industries are: Automobile, Agriculture, and Industrial. I will be discussing compression coils used in the automotive industry. It is important to note that there are four types of spring used on all vehicles made. From passenger vehicles to heavy transport trucks one of the following four is used; Coil Springs, Leaf Springs, Torsion Bars (not torsion coil spring), and Air Springs. In subsequent articles I will detail the function of the other 3 types of springs.
There are 6 different materials which coil springs are manufactured from. Automotive coil springs are usually wound using Oil Tempered, Chrome Silicone, and Chrome Vanadium wire. The following table summarizes the material and properties:

Material	Common Sizes	Properties and Uses
Music Wire	.003-.250	A high-carbon steel wire used primarily for applications demanding high strength, medium price, and uniformly high quality. Guitar and piano strings are made from this material, as are most small springs.
Oil Tempered Wire (OT)	.010-.625	This is the workhorse steel spring wire, being used for many applications in which superior strength or uniformity is not crucial. Will not generally change dimensions under heat. Can be plated. Also available in square and rectangular sections.
Chrome Silicon, Chrome Vanadium	.010-.500	These are higher quality, higher strength versions of Oil Tempered wire, used in high-temperature applications such as automotive valve springs. Will not generally change dimensions under heat.
Stainless Steel	.005-.500	Stainless steels will not rust, making them ideal for the food industry and other environments containing water or steam. 302 series stainless will expand slightly under heat: 17-7 will usually not change.
Inconel, Monel, Beryllium Copper, Phosphor Bronze	.010-.125	These are specialty alloys made into springs which are designed to work in extremely high-temperature environments, where magnetic fields present a problem, or where corrosion resistance is needed.
Titanium	.032-.500	Used primarily in air- and spacecraft. It is extremely light weight and high strength. Titanium is very expensive and very dangerous to work with.

Coils are manufactured using either a Lathe or CNC coiling machine. A Lathe is usually used on smaller quantities of coil springs. CNC coilers are used for larger quantities of coils. Lathes are manual machines utilizing mandrels to form the coil. CNC coilers are automated and position dies to form coils. Many coil springs are coiled in an annealed (soft) condition and then tempered to achieve their strength. Coils can be wound with different inside diameters, end types, and shapes. Coil springs can be found in conical or spiral wound, constant rate or variable rate, and wound with variable pitch spacing or variable thickness wire.
It is important to never heat coils without heat treat equipment and a through knowledge of techniques and time because you will destroy the spring. The heat can change the physical characteristics and reduce the elasticity of the spring.
The physics of coil springs is derived from Hooke’s law of elasticity. It states that when an elastic body is under stress its dimension changes in proportion to the applied stress over a range of stresses. The spring equation is the most common form of Hooke’s law. It is force equals spring constant measured in force per length (F=-kx).
Compression coils are the primary suspension component of the vehicles in which they are used. Most new passenger vehicles use coils on the front and rear suspension while vehicles from the 50’s, 60’s, and 70’s utilize front coils and rear leaf springs. Most 2 wheel drive light truck and vans use coil springs for the front suspension and leaf springs on the rear. . The coils are designed to resist being compressed. They store energy and release it which absorbs road shock while driving. Coil Springs are also designed to support the weight of the vehicle. Keep in mind that springs alone can’t provide a perfectly smooth ride because they are great at absorbing energy but bad at dissipating it. This is compensated by the use of dampers (shock absorbers). The shock absorber slows the compression and rebound of the coil spring producing a smoother ride.

In vehicles, coil springs can be found between the frame and the axle, between the frame and the lower control arm, or around a McPherson strut. Commonly these suspension systems are referred to as straight axle, I-beam axle, control arm suspension, and McPherson strut suspension. The straight axle and I-beam axle are considered dependant suspensions and the control arm and McPherson strut are independent suspension systems.

Get your Coil Spring in Santa Rosa from Spring Works!

Summary:
Coil springs are made of coiling a steel wire into the shape of a helix that can be stretched and then returns to its original length when released. There is compression and rebound. Coiling of springs can be either conical or spiral wound. The physicist Hooke was behind the concept that established the physics of coil springs. Spring systems can be of four basic designs. The coil springs, leaf springs, torsion bars, and air springs. In cars, coil springs can be found between the chassis and the axle, between the chassis and the control arm, and around McPherson struts.

Firestone air helper springs

Spring Works — Wed, 19 Dec 2007 03:24:33 +0000

Spring Works offers Firestone air helper springs (air bags) that fit a majority of light trucks, SUV’s, motorhomes and vans. These durable air springs allow you to maximize your vehicles carrying capacity through the use of air pressure. Making your vehicles suspension adjustable for various road and load conditions. Go here.

Firestone air helper springs will:
Keep the vehicle front end down, Level off-center loads (front-to-rear and side-to-side leveling), Reduce suspension fatigue, Increase vehicle stability and comfort, Carry loads ranging from *1000 -5000 lbs. Go here.

Eibach lowering kits

Spring Works — Wed, 19 Dec 2007 03:23:41 +0000

All Eibach products are not only developed and manufactured with a great deal of experience, but also with heart. The requirements of Motor Sports are a constant challenge to us. Approval and the goodwill of our customers - from the manufacturer of the vehicle to the individual automobile fan - are comforting applause to us. Go here.

Polyurethane or rubber

Spring Works — Wed, 19 Dec 2007 03:22:26 +0000

Rubber is the sap of trees found mostly in tropical climates. The sap is altered by mixtures of carbon (why it’s black) and mineral oils and various fillers. Polyurethane is completely chemical or man-made. Because rubber is a biodegradable product it is affected by ozone and will over time dry rot and degrade, while urethane will keep going and going. Urethane bushings will increase the performance handling characteristics of your vehicle. Urethane is a firmer material then rubber. It is more responsive then rubber. OE (Original Equipment) rubber bushings are usually softer and provide comfortable ride characteristics. Most OE bushings are rubber. Each type of bushing is suited well for the specific handling the user is attempting to achieve. Go Here.

Polyurethane bushings

Spring Works — Wed, 19 Dec 2007 03:21:57 +0000

Polyurethane is a term used to describe a wide ranging family of elastomers (any compound exhibiting the characteristics of natural rubber; stretchy and elastic.). Poly meaning “many” and “urethane” the classification of the chemical structure. Polyurethane or urethane for short, is used as a solid cast material (bushings). Polyurethane can be as soft as a rubber band or as hard as plastic.

U-Bolt replacement

Spring Works — Wed, 19 Dec 2007 03:21:24 +0000

We suggest that whenever the springs are removed and replaced, you should change your u-bolts at that time. It is a relatively inexpensive insurance policy to keep your vehicle is safe

Varible rate coils

Spring Works — Wed, 19 Dec 2007 03:20:30 +0000

Variblee rate springs defelct at different amounts per inch. An example would be: 200 lbs. = 1 inch deflection, 600 lbs. = 2 inch deflection, 1000 lbs. = 3 inch deflection, and so on. Varible coils have a soft initial spring rate and a much firmer spring rate to handle more weight, decrease sway, and improve handling. Go Here.

Constant rate coils

Spring Works — Wed, 19 Dec 2007 03:20:05 +0000

Constant rate springs defelct the same amount each inch. An example would be: 200 lbs. = 1 inch deflection, 400 lbs. = 2 inch deflection, 600 lbs. = 3 inch deflection, and so on. Constant rate coils have will restore your vehicle to its original height and ride.

Re-Arching leaf springs

Spring Works — Wed, 19 Dec 2007 03:19:28 +0000

Rearching is a process of re-curving each leaf spring to original or custom specifications. Once the springs are individually rearched they are then heat set. Heat setting is done by heating the spring to a specific tempature for a specific time.

Inspecting leaf and coil springs

Spring Works — Wed, 19 Dec 2007 03:10:45 +0000

The most common method of leaf spring inspection is checking the vehicle ride height. Measure! Don’t rely on eyesight alone! This method will only catch the extreme cases of spring sag or leaning. In addition to checking ride height, look for these signs, which also indicate the leaf spring requires attention:Examine each spring for stress cracks, missing leafs, or shiny spots between leafs.

Damaged bushings or bump stops on the frame.

Front end of vehicle nose dives when braking or vehicle sway. Spongy ride.

Vehicle that commonly carry extra weight, resulting in unlevel condition most of the time (family transportation, work trucks, and sales fleets). GO HERE.