CASE STUDY
Stress-free through milling –
How we reinvented barquette manufacturing for the watch industry.
Background
In 2011, the Industrie- und Technozentrum Schaffhausen (ITS) approached us on behalf of a watch manufacturer. The assignment: find a production partner independent of the watch industry to solve a concrete quality problem in barquette manufacturing.
The core issue: blanks were warping during and after machining – particularly when the material was subject to heavy one-sided reduction. The result was a high scrap rate and costly rework that made the entire production process inefficient and expensive.
The Challenge
The root cause lay in the manufacturing process used at the time: stamping. The enormous forces exerted during stamping – which increase with material thickness – generate internal stresses in the workpiece that are extremely difficult to control.
Thermal treatments and complex rework on already pre-formed semi-finished parts could at best partially compensate for these stresses – full elimination was practically impossible. The objective was clear: blanks had to remain flat during and after machining – without expensive corrections after the fact.
“The stresses induced by stamping are extremely difficult or impossible to fully eliminate through thermal treatments.”
The Solution
We rethought the manufacturing process from scratch. The answer: milling instead of stamping.
Chip-removal milling eliminates the massive force impact of the stamping process entirely. Technological advances in milling precision now enable a remarkably gentle machining process with high accuracy. The process is more time-intensive than stamping – but introduces zero internal stress into the material.
The result: blanks that remain flat even under heavy one-sided material reduction – without rework, without scrap, without compromise.
The Result
This project marked the beginning of our barquette production for the watch industry. A collaboration born from a concrete problem that continues to demonstrate what becomes possible when you rethink manufacturing processes without constraints.
By switching from stamping to milling, we achieved three key goals for our client:
- Significant reduction in scrap rate through stress-free blanks
- Near-complete elimination of costly rework
- Flatness of barquettes even under heavy one-sided material reduction
What is usually considered special accessories is standard at HEDELIUS: All machining centres are equipped with a CNC full keyboard, colour monitor, spindle feed overdrive and original software as standard. State-of-the-art control technology from SIEMENS or HEIDENHAIN guarantees maximum operating convenience and unrestricted functionality. You decide which system you want to work with.
All machining centres are equipped with a CNC full keyboard, colour monitor, spindle feed overdrive and original software as standard.
Liquid-cooled motor spindles with precision cooler.
The SIEMENS SINUMERIK ONE control system brings your ideas to life. SINUMERIK ONE is the future-oriented CNC system for highly productive HEDELIUS machining centres. For unimagined new possibilities, ideas and business models. For faster innovations thanks to the seamless interaction between the virtual and real worlds. And: SINUMERIK ONE is far more than just a powerful hardware innovation.
Frequently Asked Questions
Why does Wild Wetzikon manufacture barquettes by milling instead of stamping?
Wild Wetzikon mills barquettes because milling avoids the massive forces of stamping and introduces no internal stresses into the material. Stamping, by contrast, generates internal stresses that grow with material thickness and are very hard to control. Milling is more time-intensive, but it produces blanks that stay flat even under heavy one-sided reduction. This eliminates scrap and costly rework.
What problem was the case study intended to solve?
The starting point was a 2011 enquiry from the Schaffhausen Industry and Technology Centre on behalf of a watch manufacturer. Blanks were warping during and after machining, particularly under heavy one-sided reduction, which led to a high scrap rate and costly rework. What was needed was a production partner independent of the watch industry that could solve this quality problem. The objective was for the blanks to stay flat during and after machining.
Why can stamping stresses not simply be compensated afterwards?
The internal stresses created during stamping are very difficult, or impossible, to fully compensate through thermal treatments. Complex rework on pre-formed semi-finished parts could at best partially offset them. As material thickness increases, the problem intensifies further. This is why a fundamentally different manufacturing approach was necessary.
What result did the switch from stamping to milling bring?
The switch led to a marked reduction in the scrap rate through low-stress blanks and the near-complete elimination of costly rework. The barquettes stay flat even under heavy one-sided material reduction. This made the process more efficient and more economical for the customer. At the same time, it marked the beginning of our barquette production for the watch industry.
Can the stress-free milling process be transferred to other parts?
The underlying principle of producing blanks as gently as possible, without introducing stresses, can be transferred to a range of workpieces. What matters is the material, the geometry and the required flatness. Whether your part is suitable is something we clarify from the drawing and, if needed, from a sample. That way scrap and rework can be avoided from the outset.
Distortion-free blanks — principle and final values
| Attribute | Value |
|---|---|
| Principle | Milling instead of stamping — no internal stresses introduced |
| Result | flat even under heavy one-sided machining; less scrap and rework |
| Final machining | double-disc grinding, both sides simultaneously |
| Thickness tolerance | down to ±0.005 mm |
| Parallelism | down to 0.003 mm |
| Suitability | thin and heavily one-sided machined parts |
| Materials | brass, nickel silver, titanium and others by arrangement |
| Documentation | values achieved per batch; material certificate on request |
- Why are barquettes milled instead of stamped?
- Stamping introduces internal stresses that intensify with material thickness; milling removes this force input, so the blanks stay flat and scrap and rework decrease.
- What tolerances does the distortion-free production achieve after grinding?
- After milling Wild Wetzikon grinds to size in double-disc grinding, with thickness tolerances down to ±0.005 mm and parallelism down to 0.003 mm, documented and reproducible across the series.
Frequent buyer questions