Precision-engineered custom springs are the foundation of every prototype's reliability, which is why their specification must be complete as early as the conceptual stage.
Professional technical documentation for springs is a set of force, geometric, and material parameters that unequivocally determine the component's behavior in a real mechanical system. Proper definition of this data by an R&D engineer shortens the implementation process (Time-to-Market) and eliminates the risk of costly fatigue failures.
Technical parameters and the spring constant
In the R&D design phase, the heart of the calculations is the spring constant k (k = P / f). It can be compared to the precise tuning of an instrument – if this parameter is incorrectly specified, the entire mechanism will "go out of tune" under the operating load.
At Metalpol, we manufacture components from wires ranging from 0.2 to 18.5 mm. For an engineer, this means we need to know not only the target force (Fmax) but also the installation space. Providing limit dimensions (e.g., hole or shaft diameter) allows us to select the optimal number of active coils, which directly impacts the element's service life.
Comparison table of popular materials
Material selection is a compromise between the operating environment and the project budget:
| Material | Standard | Temp. Resistance | Characteristics |
| Carbon steel | EN 10270-1 | up to approx. 150–250°C | High strength, lowest cost, not corrosion-resistant. |
| Stainless steel | AISI 304/316 | up to approx. 250–540°C | Corrosion resistance, good for medical and aggressive environments. |
| Inconel / Alloys | e.g., Inconel 718, 625 | up to approx. 600–650°C (550°C+ in aerospace/energy) | High strength at temperature, typical in aerospace and energy. |
How to shorten prototype implementation time?
The most common mistakes that prolong the process are:
- Lack of tolerance definition: "Ideal" dimensions are impossible to achieve in the CNC coiling process; always specify permissible deviations (e.g., according to DIN 2095).
- Ignoring operating conditions: A spring operating at 150°C will lose its properties (relaxation) if it is made from ordinary patented wire.
- Omitting the winding direction: Important if the spring works with a thread or another spring (risk of interlocking).
Why is Metalpol a trusted partner in R&D?
We have been operating in the Special Economic Zone in Mielec for over 50 years. Our processes are certified according to ISO 9001:2015 and the rigorous IATF 16949:2016 standard, making us a proven supplier for the automotive and aerospace sectors.
We have our own measuring laboratory, which allows us to verify spring characteristics at every stage of prototyping.
Looking for support in selecting springs for your project?
Contact our engineers. Send a drawing or description to info@mtlpl.eu or call us!
FAQ
What is the minimum prototype batch?
At Metalpol, we fulfill orders starting from single pieces (prototypes), offering technical support in optimizing them for serial production.
Do you make springs based on a sample?
Yes. We can prepare documentation and the product based on a provided sample, a 3D model (CAD/CAM), or a technical drawing.
Do you offer anti-corrosion coatings?
Yes, we have an automatic zinc flake coating line that provides excellent protection without the risk of hydrogen embrittlement.
