Success with springs begins with specifying the right spring for your application. When ordering springs, it is important to have a clear understanding of spring terminology. A knowledge of the descriptive terms used in the spring industry will help you in communicating exactly what you need when placing an order, or simply describing what you need to your spring vender.
To get you started, here are some of the more commonly used descriptors that you will encounter in spring terminology:
Active Coils – Those coils which are free to deflect under load.
Body Length – The length of an extension spring in the unloaded position for the coiled part only.
Close Wound – Coiled with adjacent coils touching.
Elastic Limit – Maximum stress to which a material may be subjected without permanent set.
Free Length – The length of a compression spring in the unloaded position.
Initial Tension – The force that tends to keep the coils of an extension spring closed and which must be overcome before the coils start to open.
Load – The force applied to a spring that causes a deflection.
Pitch – The distance from center to center of the wire in adjacent active coils.
Ready to learn more spring terminology? W.B. Jones has compiled an extensive glossary of spring terms, offering you a handy reference for getting acquainted with the most widely used spring language.
As a knowledgeable and experienced spring manufacturer, our goal is not only to supply spring users with the highest quality springs, but also to offer our customers the best support and service. Our team is available to assist you in understanding everything you need to know about your spring options. Contact us to discuss your project!
Extension springs are commonly used in automotive assemblies, garage door mechanisms, hand tools, toys, trampolines, washing machines, farm equipment, and more. They are available in a wide range of sizes, from tiny extension springs for medical devices to larger sizes for industrial machinery. Extension springs are attached to other components on both ends. As the components move apart, the spring provides a force that brings them together again.
By design, extension springs are engineered to absorb and store energy by offering resistance to a pulling force. When the extension spring is slowly stretched the tension force is resisted because the spring is attempting to return to its coiled resting position. The farther the spring is extended, the greater the degree of resistance it will have.
Extension springs are usually cylindrical in shape and closed wound. End styles vary based on the application for which they are being used. By varying the diameter of the coil, wire thickness, and length of the extension spring, they can be designed to accommodate a variety of loads and application conditions. As with most spring types, extension springs can be fabricated from a number of different materials to suit individual application needs. Temperature, stress, and corrosive environments are examples of factors that will influence material selection.
W.B. Jones is a specialized and experienced manufacturer of high quality springs. Our expertise and capabilities include the fabrication of custom extension springs made to precise specifications. We assist our customers in ordering custom extension springs that meet all application requirements and work within the customer’s established budget. All W.B. Jones springs are manufactured in the U.S., and most custom orders ship within 3 to 10 days.
We’re proud to offer over a century of experience providing both stock and custom quality extension springs. Our team will work from new or existing custom designs to deliver the extension springs you need.
A wide range of spring end types are used in modern spring design. The spring end type you choose will depend on the job the spring will be doing. In some cases a spring will have two different end types. To best select the right end type or types for your spring, you’ll need to understand each end type and how they function. A spring’s end type affects its pitch, solid height, number of active and total coils, free length, and seating characteristics of the spring. Selecting the right end type for your springs begins with identifying the basic end types available for the different types of spring design:
Extension Spring End Types
The two end types most commonly used with extension springs are hooks and loops. Hooks have a gap, while loops are fully closed all the way around. Typically stock extension springs are made with loop ends. If a hook is required, a gap is cut in the loop to create the hook. Hooks and loops can be customized to meet specific application needs. The most commonly used end styles for extension springs are crossover, machine style, side style, and double loop ends.
Compression Spring End Types13
The two common end type options in compression springs are open and closed. With each of these, either ground or not ground ends can be specified. A closed or squared off end type is most often used for compression springs. For closed ended springs, the space between the last two coils is so minimal the coils actually touch and it sits flat. In contrast, open ended springs are not squared off and tend to need some type of support, such as a rod. Open ends are usually only used in special applications. Grinding the ends of compression springs helps springs sit more flat to reduce buckling.
Torsion Spring End Types
When it comes to torsion springs, the most typical and versatile end type is a plain straight leg, with no bends. Customized designs can be created for applications that require a torsion spring with bends.
Not sure which end type will best meet your project needs? Talk to our spring design experts.
Spring failure can cause costly and damaging problems for your extension spring application. In most cases of extension spring failure, the cause is stress or force that exceeds what the spring is designed to handle. For example, extension springs that are designed for strength usually have reduced elasticity, and will fail if stretched too far. The spring breakage can occur at the ends or within the body. Other reasons for failure besides a flawed spring design are unforeseen environmental issues and improper installation.
Characteristically, extension springs are more vulnerable at the ends than within the body. When the loops or hooks are formed, the wire is bent upward and the diameter of the ends is slightly decreased. This bend and reduced diameter create a considerable concentration of stress. A well-engineered spring will take this concentration into account as it leads to premature failure.
If extension spring failure occurs due to overstressing, the spring design probably needs to be adjusted. These three common changes can decrease the likelihood of breakage:
- Increase the Outer Diameter
- Decrease Wire Diameter
- Add More Coils
Obtaining accurate information about what will be required of the spring while you are in the design phase will greatly reduce the chances of extension spring failure. Such information may include the required extended length to the necessary load or the full measurements of an existing spring. The more exact the details are the less likely spring overstressing and breakage will occur.
Need assistance with an extension spring design adjustment or other spring failure problem? Our spring design experts are here to help.
W.B. Jones is your source for a wide range of stock and custom spring designs. If your torsion spring needs don’t fit within our stock selection, ordering custom torsion springs is easy with our interactive torsion spring order form. As a qualified and experienced spring supplier, W. B. Jones offers you the advantages of:
- A wide range of stock springs
- Full custom fabrication capabilities
- Online ordering or personal assistance on custom orders
- Quotes and answers the same day requested
- All products manufactured in the USA
10 easy steps will enable you to order a quote for the custom torsion springs you need. In most cases, your finalized custom torsion springs order will ship within 3 to 10 days of confirmation.
- Choose the Type of Material – Music Wire, Hard Drawn MB, Oil Tempered Wire, Stainless Steel (202), Phosphor Bronze, Brass (or specify other)
- Specify the Wire Diameter – ranges are available from .008″ to .500″
- Indicate the Inside or Outside Diameter of the Finished Spring
- Relationship of Legs – 90 degrees, 180 degrees, 270 degrees, 360 degrees (or specify other)
- Number of Coils – should end in 1/4 if 90 degrees, 1/2 if 360 degrees, 3/4 if 270 degrees or an even number if 180 degrees
- Specify Length of Leg #1 and #2
- Direction of Wind – Right Hand or Left Hand
- Select a Spring Finish – Plain, Zinc Plate, Black Oxide, Shot Peen, Passivate, (or indicate other)
- Specify the Desired Quantity Range
- Enter your Contact Information & Submit
Our online custom torsion spring order form also allows you to provide additional application-specific details, such as temperature requirements. Additional information you can provide will help our team supply you with an extension spring that works and is most cost effective.
We recommend speaking with one of our design specialists for first time orders or new modifications to existing torsion springs.
Spring life expectancy depends much on the application in which the spring is being used. Factors such as force involved, materials used, and environmental conditions all have an impact on spring life. The design of the spring also impacts how long the spring will last. When premature spring failure occurs, it is typically due to a flaw in the design of the spring.
In many cases, springs are not properly designed for the job they are doing, which leads to reduced spring life. The application of more stress or force than the design allows can lead to spring breakage or cause the spring to take set. For instance, a spring that is designed for high strength will have minimal elasticity. Damage to an extension spring can occur in the body or at the ends if the spring is extended too far.
Spring life will also be impacted by the quality of the spring wire used to fabricate them. Low quality wire can have surface or inner defects, which curtail spring performance by reducing spring fatigue strength and increasing the possibility of breakage. Choosing springs developed from high grade materials will enhance spring performance and extend spring life. It is also important to choose the right spring material for the application. For example, hard drawn wire is most commonly used for low stress applications, while high stress applications need a stronger choice, such as music wire. Since hard drawn wire is cheaper than music wire, hard drawn may be a better choice if high strength is not required.
For many applications, achieving optimal spring life requires a custom spring design. The right spring supplier will assist you in evaluating your process and determining the best, most-cost efficient design for your project.
To be assured your springs will deliver the optimal performance and spring life for your application, please contact the spring design specialists at WB Jones.
When you select springs, one of the most important considerations you have is the type of material or spring wire type that will be used to make them. Why does the wire type used for your springs matter so much? The wire used for the construction of your springs will have an impact on how well your springs will perform in the application, due to its characteristics.
Spring wire materials are chosen for particular characteristics or features such as corrosion, water resistance, and or strength. In most cases, springs are made from one of six wire materials:
- Stainless Steel – Cold drawn general purpose wire. Features include corrosion and heat resistance.
- Music Wire – Highest quality cold drawn, high carbon wire. High strength and features a good surface finish.
- Hard Drawn MB – Cold drawn wire for average stress applications. Medium strength and low cost.
- Oil Tempered – Wire is cold drawn and heat treated before fabrication. Good general purpose spring wire for torsion springs and springs that require a large wire diameter.
- Brass – Not used as commonly due to cost. Tends to tarnish and change color over time. Features good corrosion and water resistance.
- Phosphor Bronze – Not used as commonly due to cost. Cold drawn, featuring good corrosion resistance and electrical conductivity.
Gaining an understanding of wire types will enable you to select the right spring material type to offer the best performance for your particular application. The spring experts at W.B. Jones are here to assist you with spring wire material selection, from choosing the best characteristics for your project, to identifying a currently used spring type. Contact us to discuss your needs.
At first glance, springs of all types can appear to be basically the same. In reality, however, there are a wide variety of spring designs, all with differing characteristics, depending on the job they are intended to do. Two specific types of springs that are similar, but with differences are compression springs and die springs.
Of all the spring types, compression springs are probably the most common. Their basic function is to resist a compressive force. When pressure is applied, they shorten in length, storing mechanical energy while compressed. Compression springs are used in wide range of product applications, from clothes pins to electronic devices.
Die springs are compression springs, but differ from most in that they are a type of high force compression spring. Engineered to consistently give predetermined pressure at a given compression, die springs are well-suited for applications involving high loads or extreme conditions, like high temperatures. Die springs are often used in automotive applications or heavy machinery assemblies. They are a good choice for applications requiring high force within a limited area.
If die springs are stronger than most compression springs, does that mean it is always better to specify them? Not necessarily. Some of the products and assemblies in which springs are used require lighter weight and less bulk, making the heavy duty construction of die springs less conducive. When it comes to both compression springs and die springs, choice of material, wire diameter, and other variables are determined by the spring’s ultimate use and the environment in which it will function.
As a highly experienced spring manufacturer, W.B. Jones can assist you in selecting the best spring design and material for your application. Choosing the appropriate spring is crucial to application success, so our team is committed to getting spring design right. Contact us today to discuss your project.
Advanced Spring Design (ASD7) is a spring design calculator jointly developed by Universal Technical Systems and the Spring Manufacturers Institute (SMI). This helpful resource merges engineering expertise with customized calculations to aid manufacturers in quality extension spring design.
Extension springs are just one type of spring this tool serves. The ASD7 calculator also aids in the manufacture of compression springs, spiral forms, torsion springs, garter springs, snap rings, washers, beams, and torsion bars.
Developed in a completely graphical environment, Advanced Spring Design features convenient and automatic unit conversion as well as convenient access to dynamic plots and reports. The ASD7 also includes an expandable extension springs material database, a profile system for saving and incorporating frequently used input data sets, as well as exportable DXF extension springs drawings.
The ASD7 calculator allows users to enter specifications to find extension spring rates and loads. Extension springs designs can also be backsolved for any variable.
This extension spring calculator provides SMI acceptable tolerances and calculates maximum safe loads. It also warns against potential design flaws such as settling or buckling.
W.B. Jones is expert at using this technology to design Custom Extension Springs. Let us design one to meet your exact specifications.
Specifying the right torsion spring for your application is the first step in achieving project success. Obtaining an accurate torsion spring measurement is essential. It is not difficult to obtain an accurate spring measurement if you use the correct tools and follow the right steps in taking the measurement.
The required tools include a micrometer, calipers, and a ruler or tape measure. Using these tools, obtain the following four measurements:
Find the wire diameter.
To achieve the highest degree of accuracy, use a micrometer to measure the wire diameter in two different locations on the torsion spring and take the average. This will assure precise readings and accurate ordering.
Find the outside diameter.
Typically referred to as “OD”, measurement of the outside diameter should be taken in the middle of the spring, since the end coils tend to run large.
Find the inside diameter.
Use your calipers to measure the inside diameter of the torsion spring. Since this is a more difficult measurement to accurately read, it is a good idea to double or triple check the measurements.
Measure the leg length of the spring.
Measure from the center to the end. Since the center of the spring is not marked, you’ll need to use your best judgment on this measurement. Again, double and triple checking is a good idea.
Determine the angle or relationship of the legs.
There are four major angles, all based from the center of the spring – 90°, 180°, 270°, and 360° relationship of legs.
Determine the direction of the wind.
Right hand springs follow a counterclockwise rotation. Left hand springs follow a clockwise rotation.
For more details and pictures regarding torsion spring measurement, read our guide to measuring torsion springs. Keep in mind, if you have an unusual spring of any type that is not easy to measure, you can speak to a member of our team for identification and ordering assistance.