Chemical Etching Formula
SUS316 with FeCl₃+HCl

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.

Why FeCl₃+HCl for SUS316?

On SUS316, 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 SUS316 etch line runs a variant of this formula.

Process Window & Bath Control

Hold the bath at 50°C with concentration 45 °Bé (specific gravity 1.420). Across the 0.03-0.5 mm thickness range, conveyor speed runs from 0.12-6.09 m/min — thinner sheets move faster, thicker sheets slower, in roughly inverse proportion to thickness. A typical mid-range setpoint is 0.45 m/min for 0.18 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

Feature sizes scale with sheet thickness. For this formula the minimum hole diameter ranges 36-600 μm and the minimum line width ranges 100-500 μm across the 0.03-0.5 mm band, following the industry 1.2× (hole) and 1.0× (line) thickness rules. Single-side undercut ranges 6-92 μm, and the etch factor is about 2.72. Size your photomask by subtracting twice the expected undercut from each finished feature dimension.

Yield & Production Economics

This formula delivers a typical yield of 97.0% (range 96-97.4%). 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

SUS316 etched with this recipe typically ends up in precision shims, encoder discs, RF/EMI shields, surgical and dental components, fuel-cell bipolar plates, and fine filter meshes. Because chemical etching applies no mechanical or thermal load, the finished features are free of work-hardening and heat-affected zones — a decisive advantage over stamping or laser cutting for these uses.

Process Equipment & Material Reference

On the shop floor, this SUS316 + FeCl₃+HCl recipe is implemented on a wet chemical etching machine. The 50°C bath setpoint and 0.12-6.09 m/min conveyor range correspond to verified production envelopes on that equipment for through etch (double-sided).

The Stainless Steel chemical etching guide reference goes one level above the recipe shown here, surveying the full thickness range, depth options, and common subgrades we run for stainless.

Production Use Cases for This Formula

Production examples for the SUS316 / FeCl₃+HCl recipe span stainless steel shower-head filter mesh, stainless steel metal filter mesh, and stainless filtration mesh for vacuum cleaners. In every case, the etch factor and undercut figures on this page are the dominant tolerance drivers — bath maintenance discipline matters more than equipment headline rating.

If your part falls into one of these classes — or a closely adjacent one — this formula is usually the right starting point. We confirm fit with a short sample run on the actual sheet stock before locking in mask artwork.

Other Metals Etched with FeCl₃+HCl

The FeCl₃+HCl chemistry is also documented for these alloys.

More Stainless Steel Formulas

Other formulas in the same material family.

Frequently Asked Questions