Stainless Steel FeCl₃+HCl

Chemical Etching Formula
SUS2205 Duplex Stainless with FeCl₃+HCl

For engineers selecting an etching chemistry for SUS2205 Duplex Stainless, the FeCl₃+HCl formula shown here defines the bath composition, temperature window, and achievable feature sizes across a 0.1-0.5 mm thickness band. Typical mass-production yield for this recipe is 95.8%, with a typical conveyor speed of 0.23 m/min at 54°C.

Formula Summary

The table below summarizes every parameter that defines this etching formula. Values listed as ranges scale with sheet thickness across the supported band.

FeCl₃+HCl Etchant System
46 °Bé Concentration
1.430 Specific Gravity
54 °C Bath Temperature
Through etch (double-sided) Etch Depth Type
0.1-0.5 mm Thickness Range
0.25 mm Typical Thickness
0.12-0.85 m/min Conveyor Speed Range
0.23 m/min Typical Speed
120-600 μm Min Hole Ø Range
100-500 μm Min Line Width Range
20-99 μm Undercut Range
2.53 Etch Factor (EF)
95.8% Typical Yield (95-96.2%)

Why FeCl₃+HCl for SUS2205 Duplex Stainless?

On SUS2205 Duplex Stainless, the ferric chloride system attacks the alloy's oxide layer continuously while ferric ions drive dissolution. It is regenerable, compatible with standard photolithography, and produces clean burr-free edges — which is why nearly every SUS2205 Duplex Stainless etch line runs a variant of this formula.

Process Window & Bath Control

Bath control for SUS2205 Duplex Stainless in FeCl₃+HCl: temperature 54°C, concentration 46 °Bé, specific gravity 1.430. The recipe is tuned for through etch (double-sided). Conveyor speed is the primary throughput control, ranging 0.12-0.85 m/min across the supported thickness range. Check specific gravity each shift with a calibrated hydrometer and correct with fresh make-up or water as needed.

Design Rules & Tolerances

When laying out artwork for SUS2205 Duplex Stainless at through etch (double-sided), plan for a minimum hole diameter in the 120-600 μm range and a minimum line width in the 100-500 μm range, depending on the chosen sheet thickness within 0.1-0.5 mm. The etch factor of ~2.53 and undercut range of 20-99 μm determine how much the mask must be biased to land the finished dimension on target.

Design Rule Summary
• Minimum hole diameter range: 120-600 μm
• Minimum line width range: 100-500 μm
• Single-side undercut range: 20-99 μm
• Typical etch factor (EF): 2.53

Yield & Production Economics

Typical mass-production yield for SUS2205 Duplex Stainless in the FeCl₃+HCl system is 95.8%, within an observed range of 95-96.2%. The dominant yield-loss modes are photoresist pinhole defects and rinse-water contamination. Improving incoming sheet quality and photoresist coating consistency gives the highest yield-improvement leverage for this formula.

Typical Applications

Typical applications for SUS2205 Duplex Stainless processed with FeCl₃+HCl include precision shims, encoder discs, RF/EMI shields, surgical and dental components, fuel-cell bipolar plates, and fine filter meshes. The formula's tolerance band and yield make it well suited to medium-to-high-volume precision flat parts.

More Stainless Steel Formulas

Other formulas in the same material family.

AM350 Stainless Steel FeCl₃+HCl Through etch (double-sided) SUS2507 Super Duplex FeCl₃+HCl Through etch (double-sided) SUS301 FeCl₃+HCl Through etch (double-sided) SUS301 FeCl₃+HCl Through etch (double-sided) SUS302 FeCl₃+HCl Through etch (double-sided) SUS303 FeCl₃+HCl Through etch (double-sided)

Frequently Asked Questions

Minimum line width ranges 100-500 μm over the supported thickness range, per the 1.0× thickness rule. At the fine end, photoresist resolution and adhesion — not the etchant — become the limiting factors, so resist selection matters as much as bath chemistry.

Need a Quote for This Process?

WET Etched runs production wet chemical etching lines using the FeCl₃+HCl chemistry. Send us your part drawing and quantity for a full process quote.

Request a Quote Browse Formulas