Coil springs are key components in watchmaking. Their characteristics directly influence how a watch functions. The design, selection, and upkeep of these springs require an accurate understanding. For instance, the careful selection of the mainspring can help avoid unnecessary wear on the gears. This article will explore these aspects in the context of watch making, aiming to provide practical knowledge for engineers engaged in watch design and assembly. It's important to note that while the springs are a critical factor, the performance of a watch depends equally on its other components. Hence, choosing suitable parts, including the right spring, is crucial for a watch's overall functioning and longevity.

Requirements for Watch Springs

Material properties are crucial in the construction of a watch spring. Commonly used alloys such as Elinvar are characterized by elasticity and resistance to fatigue and corrosion. It also has a low coefficient of thermal expansion, which means that the performance of watches with Elinvar springs remains relatively unaffected across different temperature conditions.

The design aspects of the watch also play a role in dictating the dimensions of the watch spring: length, thickness, and winding diameter. A smaller watch design might necessitate a spring of reduced size, but it's important to remember that this may impact the spring's flexibility and resistance to deformation under applied force.

Finally, the capacity of a watch spring to store energy should be considered. A spring with greater energy storage generally lengthens the duration between windings. However, it brings with it an increased stress on the spring, which could influence its longevity. Additionally, the vibrational properties of a spring contributes to the precision of the watch's timekeeping. These factors, therefore, should be taken into account during production to minimize timekeeping deviation.

Function of Springs in a Watch

Springs are a vital part of watch mechanisms, each carrying out distinct roles. The mainspring acts as the energy store. This can be charged either through manual winding or the wearer's wrist's natural motion, storing mechanical energy. The stored energy is gradually released through a synchronized system of gears and wheels, facilitating the movement of the watch's hands. The material and size of the mainspring play a vital role in maintaining the precision of time measurement and the durability of the watch mechanism. For example, a mainspring made of stainless steel has a high tensile strength that enables it to be tightly wound, storing a large amount of energy. This results in the watch operating for a longer duration.

The hairspring is another fundamental component that pairs with the balance wheel to function as an oscillator. This oscillation determines the consistent ticking pattern of the watch. The material used for hairsprings significantly impacts the watch's precision. Hairsprings made from Invar, which is a combination of nickel and iron, have low elasticity and high stability that maintains a steady oscillation, improving accuracy. However, they are sensitive to magnetic fields which can alter their oscillations and affect the timekeeping precision of the watch. To counteract this, materials like silicon are used. These materials not only provide consistent oscillation but resist the effects of magnetic fields as well.

How to Replace Watch Springs

The replacement of watch springs involves numerous stages that require detailed attention to avoid possible damage. The first step is to open the watch case using a watch case opener kit. This step is vital, as scratches on the watch's exterior can alter its visual appeal. After opening the case, find and extract the watch movement, gripping it by the edges to minimize the chance of injuring the delicate mechanical components. Prior to proceeding, make a mental note of the spring's anchor points; these will be significant when installing the new spring.

When removing the mainspring or hairspring, watchmaker's tweezers are a preferable tool as they allow for precision and control. Both the mainsprings and hairsprings can unwind abruptly due to retained energy, thus confirming the importance of cautious handling. Upon successful removal of the spring, take exact measurements of its diameter, thickness, and length using a watch gauge. These measurements will ease the acquisition of an appropriate replacement. The installation of the replacement should also involve cautious use of tweezers and ensuring the correct alignment with the previously marked hooking points. After securing the spring, successfully finalize the reassembly of the watch, paying heed to securely fasten the casing to preserve the watch's structural integrity and water resistance.

Due to the complex nature of watch components and their replacement steps, practical experience may prove beneficial. It can significantly decrease the chance of expensive errors occurring during the process of spring replacement. Therefore, proper preparation has a tangible effect on the successful execution of spring replacement procedures.


In watch design, acquiring a solid understanding of watch springs and their specific design necessities is vital for engineers. Choosing the right material and deciding on the best spring dimensions are tasks that directly influence the performance and lifespan of the watches. Moreover, mastery in performing spring replacement operations results in better functionality of the watches. This factual knowledge significantly contributes to the basic operations in watchmaking and aids in creating the final product.