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?

Ferric-chloride-based formulas are the industrial workhorse for ferrous, nickel, and copper-bearing alloys like SUS316. The Fe³⁺ ion oxidizes the metal surface; where HCl is present it regenerates dissolved species and stabilizes chloride concentration. The result on SUS316 is anisotropic etching with predictable undercut and an easily regenerated spent bath.

Process Window & Bath Control

Bath control for SUS316 in FeCl₃+HCl: temperature 48°C, concentration 45 °Bé, specific gravity 1.420. The recipe is tuned for through etch (double-sided). Conveyor speed is the primary throughput control, ranging 0.12-1.54 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

Feature sizes scale with sheet thickness. For this formula the minimum hole diameter ranges 96-540 μm and the minimum line width ranges 100-450 μm across the 0.08-0.45 mm band, following the industry 1.2× (hole) and 1.0× (line) thickness rules. Single-side undercut ranges 15-83 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

Expect a yield in the 96.5-97.6% range for SUS316 with FeCl₃+HCl, with 97.2% typical on a well-controlled line. Most rejects trace back to upstream coating and exposure rather than to the etch bath itself, so tightening photolithography control is usually the fastest path to a higher number.

Typical Applications

Typical applications for SUS316 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.

Process Equipment & Material Reference

Process equipment for the SUS316 / FeCl₃+HCl combination is built around our plasma surface treatment machine platform — closed-loop temperature control, redundant pump headers, and metering for bath replenishment all directly affect the etch factor and yield numbers cited on this page.

If you need a wider view of stainless beyond this single recipe, our Stainless Steel chemical etching guide covers grade selection, photoresist compatibility, and typical industries that consume this metal in etched form.

Production Use Cases for This Formula

Across the markets we serve, the FeCl₃+HCl formula on this page is most often deployed for stainless steel shower-head filter mesh, stainless steel metal filter mesh, and stainless filtration mesh for vacuum cleaners. These applications share thin-feature geometries that benefit from the predictable etch factor near 2.72 and the low single-side undercut documented above.

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