Extension Springs Extension springs are designed to absorb and store energy by creating a resistance to a pulling force. All coils are active in these springs, and it is the initial tension that holds the coils together tightly. Newcomb’s production capabilities for these components meet almost any client need, from a standard cross center hook to a special-purpose extension spring, such as a stove spring used on oven doors with extended hook ends.
Common Manufacturing Specifications While we have listed some of the most common sizes, materials and manufacturing specifications, Newcomb Spring provides completely customized production on all parts. If you don’t see the part you need listed here, don’t hesitate to contact us. Whatever your needs - Newcomb Kan-Do It!
With ISO 9001 certified quality systems, Newcomb Spring offers eight manufacturing plants and a special facility focused on the needs of our customers in Mexico and Latin America. We are ready to manufacture the precision springs and metal form parts that you need.
Manufacturing Specifications
Initial Tension Most extension springs are wound with initial tension. This is an internal force that holds the coils together. The measure of the initial tension is the load necessary to overcome the internal force and begin coil separation. Unlike a compression spring that has zero load at zero deflection, an extension spring can have a preload at zero deflection (see graph). This built-in load, called initial tension, can be varied within limits, decreasing as the spring index increases.
Note that there is a range of stress (and, therefore, force) for any spring index that can be held without problems. If the designer needs an extension spring with no initial tension, the spring should be designed with space between the coils. Read more on initial tension.
Initial Tension (P1) is determined by extending the spring to a given length (L1) ensuring coil separation. The spring then is extended an equal distance to (L2). The amount of initial tension is equal to two (2) times the load achieved at (L1) minus the load at (L2). The formula for Initial Tension Simplified (Pi) = 2P1 - P2.
Extension Spring Ends Newcomb Spring parts can be produced with a variety of ends types, all of which can vary in distance from the spring body. We match all end types to your exact order specifications, and can change end hook shapes based on customer needs. As one of the industry’s leading extension spring manufacturers, we recommend discussing your requirements with a Newcomb sales engineer who can verify manufacturing capabilities and will work to keep your production costs as low as possible.
Order Information As with all Newcomb Spring-produced parts, we can custom manufacture any extension spring to fit your needs. As one of the leading extension spring manufacturers in the United States, we have offered great prices, high quality and total customer satisfaction for more than 125 years.
Contact us today, or request an extension spring manufacturing quote online and experience the Newcomb Spring difference for yourself.
Newcomb Spring is a founding member of the Spring Manufacturer's Institute. Some content here has been used with permission of the SMI.
