Wave springs are not usually cheaper than traditional coil springs when comparing the cost of the individual component. However, looking at unit price alone rarely tells the full story. When a medical device is designed specifically to accommodate a wave spring, the reduction in installation height can enable smaller assemblies, lower material usage and simplified designs that reduce overall manufacturing costs.
For medical device designers, the question should not be "Which spring is cheaper?" but rather "Which spring creates the most cost-effective device?"
Why do wave springs have a higher upfront cost ?
Wave springs generally cost more to manufacture than traditional coil springs because they require flat wire and more specialised forming processes.
By comparison, conventional coil springs benefit from mature, high-volume manufacturing methods that have been refined over many decades. They are produced in a wide variety of standard sizes, making them an economical choice for many applications.
On a purely component-by-component basis, a traditional coil spring will often have the lower purchase price.
Why doesn't the purchase price tell the whole story?
The cost of an individual spring is only one part of the overall manufacturing equation. Medical devices are made up of dozens, and sometimes hundreds, of interacting components. Choosing a spring that occupies less space can influence the size, complexity and material requirements of the surrounding assembly.
When wave springs are considered early in the design process, they can unlock wider system-level savings that outweigh the additional component cost. These savings may include:
- Reduced material usage through smaller housings
- Fewer or simpler supporting components
- More compact product designs
- Improved packaging efficiency
- Reduced overall assembly complexity
Instead of evaluating the spring in isolation, engineers should consider its impact on the total cost of the finished device.
How can wave springs reduce manufacturing costs?
The biggest financial advantage of a wave spring comes from enabling better product design. Because wave springs achieve comparable compression performance within a significantly reduced installation height, designers gain greater flexibility when packaging internal components. A smaller spring cavity can allow the entire device to become more compact or free space for additional functional features without increasing overall dimensions.
For high-volume medical products such as autoinjectors, pen injectors and wearable drug delivery devices, even modest reductions in material use can become significant across large production runs. Likewise, simplifying an assembly can reduce manufacturing time, improve automation and lower the likelihood of production issues that contribute to scrap or rework.
These indirect savings often have a far greater financial impact than the cost difference between two spring types.
When is a traditional coil spring the more economical choice?
Traditional coil springs remain the most cost-effective solution in many applications. If installation height is not a limiting factor and there is little opportunity to reduce the size of the surrounding assembly, a conventional coil spring may deliver the required performance at a lower overall cost.
Similarly, replacing an existing coil spring with a wave spring rarely produces immediate savings. Because wave springs require different cavity dimensions, changing spring type often requires a redesign of the surrounding mechanism.
For established products, the engineering effort involved may outweigh any potential commercial benefit.
How should engineers compare spring costs?
Rather than comparing component prices alone, engineers should evaluate the total cost of ownership throughout the product lifecycle. Questions worth considering include:
- Can a smaller spring reduce the size of the overall device?
- Will fewer materials be required?
- Can assembly become simpler or more repeatable?
- Will the design support high-volume automated manufacturing?
- Could a redesigned assembly reduce long-term production costs?
Looking at the wider picture often leads to better engineering and commercial decisions than focusing solely on the price of an individual component.
Looking beyond component cost
The cheapest spring is not always the most economical choice. Whilst it's true that traditional coil springs often have the lower purchase price, wave springs can create value elsewhere in the design by enabling smaller, lighter and more efficient medical devices.
At Advanex Medical, we help engineers evaluate component decisions in the context of the entire assembly. By considering manufacturability, repeatability and long-term production efficiency from the outset, we help reduce development risk and support cost-effective medical device manufacturing at scale.
To find out more about how we can enhance your manufacturing processes, download our guide below.
