Precision Springs

Precision Springs

07 Materials and Design Features 10 Comparison: Standard Springs vs. Precision Springs

In engineering, springs are generally known as standard parts manufactured through cold or hot forming from alloyed or unalloyed spring steels with round, square, or rectangular cross-sections. Springs machined from a single piece of material, on the other hand, are less common. These springs can absorb compressive, tensile, and torsional forces as well as bending stresses. Their particular advantage lies in the targeted combination of different spring characteristics within a single component. Compared to coiled springs, they enable very precise and constant spring rates of up to ±0.1% as well...

Force distribution Single-coil compression spring Precision spring No unwanted lateral buckling with a double- or multi-coil precision spring. Single-coil spring Double-coil spring In precision springs manufactured by machining, both left- and right-handed coils can be combined within a single spring. This effectively prevents unwanted twisting of the spring ends.

6 Maximum Accuracy in Precision Springs The machining process used to manufacture precision springs does not generate any additional internal stresses that must be overcome when the spring is loaded. Furthermore, due to the high manufacturing accuracy, all coil windings are active. As a result, the spring deforms uniformly under load and returns to its original shape once the load is removed. The result is a linear and precise spring characteristic curve. For conventionally wound springs, the spring rate typically falls within a tolerance range of approximately ±10%. Machined precision springs,...

Wide Range of Materials for Precision Springs Conventional coiled springs are usually made from spring steel wire in accordance with EN 10270-1. For machined precision springs, however, the choice of materials is significantly broader, since the material does not need to be formed but only needs to be machinable. This allows, for example, the following materials to be used: • Aluminum for particularly lightweight springs • Plastics for electrically insulating applications • Titanium for high-strength and corrosion-resistant precision springs Typical Applications and Dimensions Compression and...

Optimized Fastening for Precision In traditional coiled spiral springs, fastenings are often achieved using bent wire ends, hooks, rings, or ground spring ends. However, these small bend radii often result in high material stresses and can lead to premature component failure. Furthermore, these connection points can only transfer the torques generated in the spring to adjacent components to a limited extent. Machined precision springs offer design advantages in this regard. Fasteners can be specifically integrated into the component and reinforced where forces need to be transmitted. Typical...

9 Extending Service Life The service life of precision springs can be extended through various design measures. Typical optimizations include: • Stress-relief holes at the coil end to reduce notch stress • Material reinforcements in the critical area of the coil • Surface coatings such as nickel plating to improve wear resistance and corrosion protection These measures increase the number of possible load cycles and improve the spring’s fatigue strength. Stress relief bores Integrated functions to reduce the number of components Thanks to the design possibilities of machined precision springs,...

Precision springs Standard Springs • Usually available only in single-coil designs • Mounting options are limited and can typically only be added after production • Precise inner or outer diameters often require additional grinding processes • Different spring types (compression, tension, or torsion springs) cannot be combined • Material-related residual stresses affect performance • Spring rates may vary within a single production batch • Limited material selection • Possible deviations in parallelism or buckling under load • Integrated additional functions can only be achieved using multiple...