Chemical Etching Formula
SUS304L 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 SUS304L?

Ferric-chloride-based formulas are the industrial workhorse for ferrous, nickel, and copper-bearing alloys like SUS304L. The Fe³⁺ ion oxidizes the metal surface; where HCl is present it regenerates dissolved species and stabilizes chloride concentration. The result on SUS304L is anisotropic etching with predictable undercut and an easily regenerated spent bath.

Process Window & Bath Control

Bath control for SUS304L in FeCl₃+HCl: temperature 48°C, concentration 44 °Bé, specific gravity 1.410. The recipe is tuned for through etch (double-sided). Conveyor speed is the primary throughput control, ranging 0.12-6.69 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 SUS304L at through etch (double-sided), plan for a minimum hole diameter in the 36-600 μm range and a minimum line width in the 100-500 μm range, depending on the chosen sheet thickness within 0.03-0.5 mm. The etch factor of ~2.81 and undercut range of 5-89 μm determine how much the mask must be biased to land the finished dimension on target.

Yield & Production Economics

Expect a yield in the 96.4-97.8% range for SUS304L with FeCl₃+HCl, with 97.4% 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

Parts produced with the FeCl₃+HCl formula on SUS304L 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.

Process Equipment & Material Reference

Process equipment for the SUS304L / FeCl₃+HCl combination is built around our wet chemical etching 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 cold-press juicer filtration mesh, stainless filtration mesh for vacuum cleaners, and stainless steel shower-head filter mesh. These applications share thin-feature geometries that benefit from the predictable etch factor near 2.81 and the low single-side undercut documented above.

Adjacent applications usually transfer onto this same formula with no chemistry change, sometimes only a conveyor speed tweak. Drop a drawing and a target volume and we will return a process card built off the parameters on this page.

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