Stainless Steel FeCl₃

Chemical Etching Formula
SUS430 with FeCl₃

Working with SUS430 on a chemical etch line begins with the right formula. The FeCl₃ system documented below produces through etch (double-sided) across 0.01-0.5 mm sheet, with a minimum hole-diameter range of 8-600 μm and a minimum line-width range of 100-500 μm. The numbers scale with thickness — thinner stock yields finer features.

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 Etchant System
40 °Bé Concentration
1.380 Specific Gravity
48 °C Bath Temperature
Through etch (double-sided) Etch Depth Type
0.01-0.5 mm Thickness Range
0.10 mm Typical Thickness
0.12-78.25 m/min Conveyor Speed Range
1.15 m/min Typical Speed
8-600 μm Min Hole Ø Range
100-500 μm Min Line Width Range
1-88 μm Undercut Range
2.85 Etch Factor (EF)
97.5% Typical Yield (96.4-97.8%)

Why FeCl₃ for SUS430?

Ferric-chloride-based formulas are the industrial workhorse for ferrous, nickel, and copper-bearing alloys like SUS430. The Fe³⁺ ion oxidizes the metal surface; where HCl is present it regenerates dissolved species and stabilizes chloride concentration. The result on SUS430 is anisotropic etching with predictable undercut and an easily regenerated spent bath.

Process Window & Bath Control

Hold the bath at 48°C with concentration 40 °Bé (specific gravity 1.380). Across the 0.01-0.5 mm thickness range, conveyor speed runs from 0.12-78.25 m/min — thinner sheets move faster, thicker sheets slower, in roughly inverse proportion to thickness. A typical mid-range setpoint is 1.15 m/min for 0.10 mm stock. Use redundant PID temperature control to hold the bath within ±1.5°C, and titrate at least once per shift.

Design Rules & Tolerances

When laying out artwork for SUS430 at through etch (double-sided), plan for a minimum hole diameter in the 8-600 μm range and a minimum line width in the 100-500 μm range, depending on the chosen sheet thickness within 0.01-0.5 mm. The etch factor of ~2.85 and undercut range of 1-88 μm determine how much the mask must be biased to land the finished dimension on target.

Design Rule Summary
• Minimum hole diameter range: 8-600 μm
• Minimum line width range: 100-500 μm
• Single-side undercut range: 1-88 μm
• Typical etch factor (EF): 2.85

Yield & Production Economics

This formula delivers a typical yield of 97.5% (range 96.4-97.8%). At that rate, per-part economics are driven mostly by fixed photomask and setup cost for small batches and by sheet utilisation for large runs. The chemistry itself does not change with quantity, so the same recipe serves prototype and production volumes.

Typical Applications

Parts produced with the FeCl₃ formula on SUS430 are common in precision shims, encoder discs, RF/EMI shields, surgical and dental components, fuel-cell bipolar plates, and fine filter meshes. The burr-free, stress-free nature of chemical etching makes it the preferred process wherever flatness and edge quality matter more than raw throughput.

More Stainless Steel Formulas

Other formulas in the same material family.

AM350 Stainless Steel FeCl₃+HCl Through etch (double-sided) SUS2205 Duplex Stainless 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)

Frequently Asked Questions

Target specific gravity is 1.380 for this formula. Check it each shift with a calibrated hydrometer. A falling SG indicates the bath is becoming depleted; a rising SG usually points to evaporative water loss that should be corrected with controlled water addition.

Need a Quote for This Process?

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

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