In high-precision engineering, the difference between a perfectly functioning machine and a catastrophic failure often comes down to a fraction of a millimeter. Stainless steel shims are the essential components used to take up “play,” align parts, and ensure perfect spacing within mechanical assemblies.
While these spacers might seem simple, the method used to manufacture them is critical. As industrial tolerances tighten in sectors like aerospace and medical device manufacturing, traditional stamping is being replaced by the far more accurate process of chemical photo etching.
The Evolution of the Shim: Beyond Stamping
For decades, metal shims were produced via power stamping. However, as designs have evolved to require thinner gauges and more complex shapes, the limitations of stamping have become apparent.
1. Zero Edge Roll or Burrs
When a mechanical punch hits a sheet of stainless steel, it causes “edge roll”—a slight rounding of the material—and leaves behind burrs. For a shim to provide an accurate adjustment, it must be perfectly flat from edge to edge. Photo etching uses a chemical process to dissolve unwanted metal, resulting in perfectly vertical profiles and burr-free edges without the need for secondary finishing.
2. Stress-Free and Flat
Stainless steel is prone to internal stresses when subjected to the high-impact force of a stamping press. This can cause the shim to bow or warp, compromising the alignment of the assembly. Photo etching is a non-contact, cold process. By removing metal atom-by-atom, the material’s integrity and absolute flatness are preserved.
3. Ultra-Thin Precision
Many modern applications require “foil shims” that are incredibly thin. Stamping these parts often leads to tearing or distortion. Photo etching excels at processing stainless steel foils as thin as 0.010mm, providing consistent accuracy that mechanical methods cannot match.
Applications of Photo Etched Stainless Steel Shims
The durability and corrosion resistance of stainless steel make these shims ideal for harsh environments:
- Aerospace & Defense: Shims for turbine blade alignment and airframe assembly where weight and precision are non-negotiable.
- Medical Technology: Precision spacers for surgical instruments and diagnostic imaging equipment.
- Automotive: Shims for gearbox assemblies and fuel injection systems.
- Electronics: Thermal management spacers and internal housing alignments.
Why Choose Stainless Steel?
While shims can be made from various materials, stainless steel remains the premier choice due to:
- Corrosion Resistance: Grades like 316L are essential for marine or medical use.
- High Strength: Maintains thickness even under extreme compressive loads.
- Hardness: Resistant to wear and deformation over long-term operation.
Custom Solutions and Rapid Prototyping
One of the greatest advantages of photo etching is the use of digital tooling. If your project requires a custom shim shape or a specific set of varying thicknesses for testing, you don’t have to wait weeks for a steel die.
At BlazeAsia, we can move from a CAD drawing to a finished prototype in a matter of days. This allows engineers to iterate designs quickly and cost-effectively, scaling up to high-volume production with 100% dimensional repeatability.
Whether you need standard circular washers or complex, multi-holed alignment shims, our photo etching service provides the precision your application demands.
Visit www.blazeasia.com for more information.