The Leader in Single and Double Coil Springs

Have a design or ordering question?

Master Spring is here to answer all your spring and wire form design questions—from measuring wire dimensions and standard spring sizes to tackling tight tolerances and much more. Browse our list of frequently asked questions below. If you have specific questions about wire sizes, tolerances and applications, we invite you to contact us or explore our Technical Resource Center.

1. Do you stock standard spring and wire form parts?

No. We manufacture all parts per your print, sample, or specifications. However, we can be a more economical source for standard or catalog springs when quantities reach production levels. We keep your blanket orders in stock and deliver per your just-in-time releases.

2. How can I save money on my custom spring order?

Cost is always a concern for product designers and purchasing agents.

Savings can be addressed in the following ways:

1. Material: Different material properties cost more than others. Consider operating environment and corrosion. Learn more.
2. Finishing:Does the material need to be electroplated or can a pre-plated material be used? Is the part used in a manner where passivation is necessary? Is the concern aesthetic, function, or both? Learn more.
3. Packaging:Do the parts need to be packaged a specific way to aid in assembly? Is tangling an issue? Is standard quantity per box a requirement? Should parts be bagged? Learn more.
4. Quantity:Blanket orders are encouraged so that we can lock in material costs and be assured of material availability. A higher quantity decreases piece price and can result in a more competitive bottom line for the user. Learn more.

3. Do you have a quality assurance system?

Yes. Our quality system is based on ISO 9001. We are certified to ensure that our springs and wire forms consistently meet customers’ requirements and that quality is continuously improved. Our goal is to provide our OEM partners with predictable quality and supply. We are proud of our quality system. Learn more.

4. Can I get a rapid prototype order?

Yes. We work with engineers from established OEMs on rapid prototype orders. Our goal is to develop long-term partnerships with OEMs where we support all their spring and wire form needs, from prototypes to production quantities. We prefer not to work with solo inventors or design engineering firms that only order prototype quantities.

Our knowledgeable staff can help OEM engineers throughout the challenging phase of prototyping by offering advice and design review. Learn more about our rapid prototyping services or contact us for more information.

5. Do you make your own tooling?

Yes. Master Spring has the machinery, skills, and experience to make in-house tooling to save cost and time. We normally purchase a full set of standard tooling that covers the wire diameter range for each machine that we own. Most orders do not require custom tools because of our large tooling inventory and the flexibility of our high-tech forming machines.

6. Do you prevent springs from tangling in their packaging?

Yes. We have several means to prevent tangling in packaging and shipment. Some methods include bagging, paper layering, placing parts on a tack-a-board, and stringing parts. These methods can be discussed at the time of quotation. Learn more about this service now.

7. What are important considerations in spring design?

Smart spring designs are dependent on factors such as dimensional and load requirements. Throughout the spring engineering process, our experts also consider:

1. Environment:Will the spring be operating in a cold or hot environment? Will it be in contact with corrosive media? If so, what kind?
2. Life expectancy:How long must the spring survive or work under the specified conditions without breaking or setting?
3. Load:Is a load required, and if so, over what range of deflection must it be maintained? What is the frequency and velocity of the load application?
4. Space:Where will the spring be functioning? During what application and in how much space? Is there sufficient room for the spring to operate fully without causing high stress that can increase the risk of failure?

8. What kind of tolerances can be imposed on a design?

Tolerances should allow spring makers to fabricate quality parts by ordinary production means in the most economical way. Therefore, the critical dimensions should be determined early in the engineering process to allow the spring maker to adjust or compensate for allowable variations in both wire size and mechanical properties.

Product designers often impose the standard tolerance box for machined dimensions on spring designs—which proves impractical based on history and the nature of spring materials. Such boxes must be reviewed, and more realistic tolerances applied.

At Master Spring, our team helps product designers determine what is critical and what specific tolerances should apply. Please call us at 708-453-2570 for spring engineering tips.

9. The print says, “Remove all burrs and break all sharp edges.” Does this affect performance and/or cost?

Burrs can be minimized during the wire forming process. However, sharp edges are a natural result of the cut-off operation. Sharp edges are generally harmless and their removal can increase cost without adding value to the spring’s performance. Give a second thought to adding the requirement to your drawing.

10. Does stress relief change a spring’s dimensions?

Stress relieving does change spring dimensions. Temperature and length of time in the oven, as well as material type, affect spring dimensions. Our experts anticipate these changes and work to ensure your final product meets your specifications. In general, the following is true:

Stress relieving or heat treating affects the type of springs as follows:

1. Extension:reduction in initial tension; change in hook position; change in spring diameter
2. Compression:reduction in initial tension; change in spring diameter
3. Torsion:reduction in initial tension; low temperature stabilizes position of ends

If you change a wire diameter by 1%, your spring rate will change by 4%. An increase in wire size by 1% results in a 4% stronger spring. The converse is also true. A decrease in wire size of 1% results in a 4% weaker spring.

12. If I change the material size by 1%, how much change in torsional stress will I get?

You will get a 3% change in torsion stress on the spring wire size.

13. What is the effect of changing the mean diameter by 1%?

If you increase the mean diameter by 1%, the change in spring rate will decrease by 3%.

14. If I add a coil, what does that do to the rate?

Adding a coil weakens the rate. Removing a coil strengthens the rate. For example, if you have a compression spring that has 10 active coils and a spring rate of 90 lbs./inch, and you want to get a rate of 100 lbs., how many active coils do you need?

Formula:

• Step 1: Single Coil Rate = (# of Active Coils) X (Spring Rate)
• Step 2: Active Coils = (Single Coil Rate) / (Spring Rate Required)

Final Answer: # Active Coils

Solution:

• Step 1: Single Coil Calculation = (10 Active Coils) X (90 lbs./inch) = 900 lbs./inch rate
• Step 2: Active Coils Calculation = (900 lbs./inch rate per single coil) / (100 lbs. rate required) = 9

Final Answer: 9 Active Coils

15. What types of finishes are available?

Master Spring & Wire Form Co. offers several coating options to improve the look or durability of your products. These finishes require additional lead times and may increase cost. Finishes may prove cost effective down the road by improving life and performance of a spring.

Zinc plating

• Description:
  Electroplating; available in clear, yellow, black, and other colors
• Benefits:
  Enhances appearance and performance
  Improves resistance to chips and abrasion

Passivation

• Description:
  Acid treatment of stainless steel to remove contaminants
  Recommended for medical and food industries
• Benefits:
  Cleans product
  Improves corrosion resistance

Other

1. Anodizing:Available in clear or various colors
2. Black oxide:Results in a black appearance
3. Chrome:Decreases surface friction; provides resistance to erosion
4. Copper:Often used in electronic applications
5. Dykem:Process where parts are dipped; good for identification purposes
6. Nickel/Tin:Bright and shiny in appearance
7. Paint or Powder Coat:Numerous colors available