Edge Welded Bellows — Technical Guide

What Are Edge Welded Bellows?

Edge welded bellows are precision metal diaphragms manufactured by welding
thin metallic discs alternately at their inner and outer diameters to form a
flexible, leak-tight convolution structure. Unlike hydroformed bellows, edge
welded bellows deliver superior stroke length, higher cycle life, and
tighter spring rate control — making them the preferred choice for
demanding high-vacuum (HV) and ultra-high-vacuum (UHV) applications.

At Alpha Technology, we produce custom edge welded bellows in materials
including SS316L, AM350, and Inconel, with OD ranges from 6mm to 200mm+,
serving semiconductor, aerospace, medical, and scientific research industries
worldwide.

Technical Resources

📐 Specification Catalog

Complete AT-Series model database with OD/ID dimensions, wall thickness,
and spring rates. Find the exact bellows for your design envelope.

View Specs →

🔬 Material Selection

Detailed comparison of SS316L, AM350, and Inconel: corrosion resistance,
temperature range, magnetic properties, and cost.

Compare Materials →

⚙️ Design & Selection Guide

How to calculate spring rate, determine stroke length, select convolution
geometry, and specify end fittings.

Design Guide →

🏭 Manufacturing Process

From diaphragm stamping to precision micro-plasma welding and helium leak
testing — see how we build bellows that last millions of cycles.

See the
Process →

Parameter Edge Welded Hydroformed
Stroke Capability ✅ Up to 60% of
free length		 ~15-20% of free length
Cycle Life ✅ 1M+ cycles
typical		 50K-100K cycles typical
Spring Rate Precision ✅ ±5% ±15-20%
Wall Thickness 0.05mm – 0.5mm 0.08mm – 0.3mm
Vacuum Compatibility ✅ UHV (10⁻¹⁰
Torr)		 HV (10⁻⁶ Torr)
Cost Efficiency Higher for low volumes Better for high
volumes

Edge Welded vs. Formed Bellows

Parameter Edge Welded Hydroformed
Stroke Capability ✅ Up to 60% of
free length		 ~15-20% of free length
Cycle Life ✅ 1M+ cycles
typical		 50K-100K cycles typical
Spring Rate Precision ✅ ±5% ±15-20%
Wall Thickness 0.05mm – 0.5mm 0.08mm – 0.3mm
Vacuum Compatibility ✅ UHV (10⁻¹⁰
Torr)		 HV (10⁻⁶ Torr)
Cost Efficiency Higher for low volumes Better for high
volumes

Applications by Industry

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