Frequently Asked Questions

To submit a custom order, we will first need to know your product requirements. We then work with you to refine your specifications as required before the quote is accepted. After the quote is accepted, we will process the order. The order may:

• Be for prototypes for you to evaluate
• Require the first piece approval before we finish the balance order.

Last, we will conduct quality assurance prior to delivering the final product.

The lead time for custom orders could be influenced by various factors such as tooling requirements or material availability. Our internal tool and die department and raw material vendors ensure to expedite this process.

In addition to manufacturing capabilities, John Evans’ Sons has a fully staffed and experienced engineering department. Our engineering team is happy to discuss your design requirements and equipment challenges. Even if you don’t know exactly what you need, we are here to help.

We have standard tooling available, but we are also able to develop custom tooling to support your custom projects. Since we offer in-house tooling, we can reduce project lead time and cost.

Yes. We often have stock of constant force springs available for college or university students. For other types of springs, a custom order would need to be placed to meet customer requirements. To see if we have products available, or speak with John Evans’ about developing a partnership, please contact us.

A contract manufacturer will often produce a product faster than manufacturing in-house. This is advantageous if your device needs to go to market quickly. In addition, a manufacturing partner can offer expertise to help guide your product decisions. They will work with you through every phase of the project.

John Evans’ Sons specializes in manufacturing difficult and challenging spring products, as well as high-volume precision springs. Window balance springs are one of our most successful products. We are known for our spring products used in aerospace and medical industries as well. Our capabilities enable us to serve a variety of applications and industries. If you have a proprietary device or your industry is not mentioned on our website, we encourage you to speak with us about your product requirements.

As America’s first springmaker, John Evans’ Sons was established on March 8, 1850. John Evans, Founder of John Evans’ Sons, Incorporated, opened his business in New Haven, Connecticut. With our dedication to innovation, we continue to prove time and again why America’s Oldest Springmaker is also its best.

Based in Lansdale, Pennsylvania, we manufacture springs, metal stampings, and mechanical assemblies. Our products serve a wide variety of applications from military to medical to high-tech. We provide impeccable service from start to finish and set the standard for world-class precision spring products.

John Evans’ Sons is proud to be American Architectural Manufacturers Association (AAMA) Qualified. In addition, we are certified to ISO Quality Management Systems: ISO 9001:2015, ISO 13485:2016, and AS9100:D. View our current ISO certifications and other affiliations.

Yes, there are several YouTube demos available for constant force window balance systems.

In lieu of a detailed drawing, we may ask for additional information to provide a more accurate quote. Our customer service and engineering team are happy to assist.

The life of our products is affected by many factors. The speed of deflection, environment, the range of deflection and the repeatability of the deflection. The life cycle is rated as a guidance and not a guaranteed number.

A power spring is the source of retraction in a tape measure. The force generated by the spring is not constant and increases as it is extended. The tape portion of the tape measure does not exhibit any spring properties. It is a flat coil of material wound around the spool that contains the power spring.

While the Seller will make every effort to supply quality products, the Buyer shall assume responsibility for the inspection of all parts when received. Parts not in accordance with the agreed upon specification must be returned to Seller within 60 days after delivery to Buyer. Upon verification by the Seller of non-conformance to specification of said returned parts, Seller may replace same, or at Seller’s option, credit in lieu thereof shall be issued. Seller’s liability for products not conforming to specification shall be limited to the sales price of such products, and Seller shall not be liable for any expense or damage to Buyer resulting from the condition or use of such products.

A single spring can achieve a maximum of 60 lbs. Through options of using multiple springs, either back-to-back or in tandem or laminating the coils together higher loads can be achieved. Our ability to customize designs to suit your requirements allows us to work with you to achieve those requirements in a cost-efficient and timely manner.

John Evans’ Sons constant force springs are in countless applications, including the Mars rovers Curiosity and Perseverance. Constant force spring mechanisms apply constant force throughout their entire length, preventing them from uncoiling while in use. We design and manufacture standard and custom constant force springs for a broad range of applications, some of which include: counterbalances (windows, doors), surgical devices (clamps), stored energy (motor systems), brush springs (motors), and clamps.

Common extension, motor types (i.e.: A-motor and B-motor), RW type springs, Multiple springs in a radius around a common drum, one coil or saddle type.

The most commonly used materials in the construction of the spring are: 301 stainless steel, Inconel, and high carbon steel.

The best constant force spring material varies depending on the type of environment it will be used in, such as corrosive and high-temperature environments, which can also affect the overall life of the spring and selected material.

Many design factors will affect the time and cost needed to manufacture your spring- Mounting methods, material, diameter, and load. All of these, plus other technical considerations, need to be discussed and specified prior to creating prototypes.

The life of a constant force spring is rated by the number of cycles it can perform before it begins to break, warp, or exhibit inconsistent constant return force. Springs are typically rated from 2,500 cycles to more than 1 million cycles.

The spring life varies and is dependent on the specific application as well as the following performance considerations:

• Material Thickness & Coil Diameter
• Type of Material
• Material Edge Condition
• Chemical Agents
• Temperature
• Speed & Acceleration
• Stability
• Backbend
• Lubrication

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The inherent friction within the reel system acts as an additive force when extending, but an opposing force when retracting.

No, a B-Motor spring would have a constant force spring attached to a cable.

The PR100 and PR200 series are the only ones with an optional base. It’s not strong enough or large enough to accommodate our larger reels.

Our .320” square hole arbors are sized to mate well with a .3125” (5/16”) carriage bolt, available at your local hardware store. Alternatively, square tubing can be used which is more common in weldments.

Typical applications include– Door closers, hose retrievers, retail display theft protection, and tool balancers.

In open reels (i.e.: arbor reels) the cable is exposed, wrapped around the exterior circumference of the reel, and contained between two flanges. Enclosed reels are simply open reels within a closed envelope or package.

The life of a spring reel is affected by many factors. The speed of deflection, environment, the range of deflection, and the repeatability of deflection. If a spring reel is used over the full travel with every deflection the reel could have a cycle life of 10,000 cycles. If the middle third of travel is used the cycle life could be closer to 50,000 cycles. The cycle life is rated as a guidance and not a guaranteed number.

Due to the friction (hysteresis) there is an increased extension load which lessons on retraction.

Installation is simplified and cable fittings are more rapidly applied.

Arbor diameter, case inner diameter, case depth/width, amount of deflection (turns or degrees), the torque required, and material type (i.e.: stainless steel or carbon steel).

Due to the highly customizable nature of these springs, we are not able to stock samples, but we are happy to quote custom solutions tailored to your individual needs.

The life of a spiral torsion spring is affected by many factors. The speed of deflection, environment, the range of deflection and the repeatability of the deflection. The cycle life is rated as a guidance not a guaranteed number.

John Evans’ Sons manufactures two types of spiral torsion springs– spiral and brush springs.

The common materials for spiral torsion springs are 302 stainless steel and carbon steel in various tempers, as well as specialty alloys. At John Evans’ Sons, we can accommodate any custom specification or configuration required, including but not limited to hooks, tabs, holes, and fasteners.

High torque can be achieved in a small amount of deflection, with a smooth and linear force increase through the majority of the working range.

Motion applications that require short rotation (less than 360°) use spiral torsion springs, where torque is desired but the number of rotations is less than 3 max, and most typically one rotation or less. They achieve a large amount of torque through a smaller amount of rotation than power springs.

Yes. Spring material can be purchased pre-tempered provided the hardness remains constant so the desired torque can be achieved with consistent results and the spring is formable.

The angle is easier to control and it is easier to roll springs therefore not as hard on the tooling.

There are fewer operations, less handling, reduced chances of mistakes/rework, and lower costs.

The life of a PUSHER variable force spring is affected by many factors. The speed of deflection, environment. The range of deflection and the repeatability of the deflection. The cycle life is rated as a guidance not a guaranteed number.

PUSHER variable force springs provide a range of force, are made of corrosion-resistant material, have multiple standard end details and widths, and are easy to mount and use.

Most POP PUSHER applications rely on these springs’ ability to accommodate different loads at different positions to push the products forward. Because pusher springs provide a varying amount of force based on the amount of deflection, variable force springs are ideal for horizontal displays like pusher trays or vertical displays in which products must be up-fed. Variable force springs can support a wide range of product weights, from lightweight video games and cosmetics to heavy cases of soda bottles.

We offer two standard types of variable force springs the ¼” wide series and the ½” wide series. Additionally, we can customize this product to meet your load, deflection and attachment requirements in the most economical way.

Variable force spring benefits:

• Cost efficiency- variable force springs consistently position products at the front of the shelf, eliminating the need for employees to do that task.
• Control- they allow for better control and ease of use when products are removed from the shelf.
• Product Integrity- variable force springs operate based on the weight of the products they are pushing.

At minimum: weight, size of unit and type of application (i.e.: smooth road, off-road, shipping cases, aircraft). Anticipated mounting orientation (i.e.: base of the unit, hanging from wall).

The application the isolator is used in has a direct bearing on what the rated capacity will be. A specific isolator can have a load capacity of 25-35 lbs. for one type of application and 45-55 lbs. for a different type of application.

The selection process requires trained personnel to evaluate the application requirements to determine the proper spring rate, natural frequency and deflection for the isolator selected. This is not typically a process for the end user.

The life of helical isolators is affected by many factors. The speed of deflection, environment, the range of deflection and the repeatability of the deflection. The cycle life is rated as a guidance and not a guaranteed number.

Helical shock and vibration isolators protect a broad range of loads in a wide range of applications, provide all-axis isolation, work in any orientation, resist destructive environments, and have a compact envelope.

Typical applications for helical shock and vibration isolators include: shipboard, rough terrain vehicles, aircraft, shipping cases, industrial equipment, ordnance equipment, medical equipment, chimneys, and more.

Shock and vibration affect the performance and lifespan of mechanical and electrical devices.

Helical shock and vibration isolators are designed to protect sensitive systems from damage due to shock and vibrations on all axes. In addition to keeping end-users safe, our isolators provide the highest level of isolation protection available. Also referred to as helical mounts, cable mounts, or spring vibration isolators, these products reliably absorb vibrations and shock due to their durable stainless steel cable construction and resilient helix configuration.

Arbor diameter, case inner diameter, case depth/width, the required number of rotations, the torque required, and material type (i.e.: stainless steel or carbon steel).

Due to the highly customizable nature of these springs, we are not able to stock samples, but we are happy to quote custom solutions tailored to your individual needs.

Yes. Assembly components not made by John Evans’ Sons can be sourced or directly supplied by our customers for incorporation directly into the assembled product. This reduces inherent difficulties that occur when combining components from several suppliers.

We offer competitive earnings, the potential for yearly performance bonuses, and excellent benefits. For immediate consideration, please e-mail your resume along with current earnings and salary requirements to jobs@springcompany.com.

Email your resume and salary requirements to jobs@springcompany.com.

A High school diploma or GED is required.

Our employees are the company’s most valuable asset. Only by hiring quality employees, has the company managed to adapt and grow since 1850. All employees receive market-competitive compensation and benefits, and they are continually supported through ongoing training. John Evans’ Sons, Incorporated, is a small business and is committed to Equal Opportunity in Employment (EOE).

Email your resume and salary requirements to jobs@springcompany.com.

Monday through Friday 8 AM to 5 PM EST.

1 Spring Avenue, P.O. Box 885, Lansdale, PA 19446 NOTE: If you are using a GPS or internet mapping, locate 7th Street and Maple Avenue.