Chemical Etching Formula
H62 brass with FeCl₃

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 for H62 brass?

Ferric-chloride-based formulas are the industrial workhorse for ferrous, nickel, and copper-bearing alloys like H62 brass. The Fe³⁺ ion oxidizes the metal surface; where HCl is present it regenerates dissolved species and stabilizes chloride concentration. The result on H62 brass is anisotropic etching with predictable undercut and an easily regenerated spent bath.

Process Window & Bath Control

Hold the bath at 44°C with concentration 38 °Bé (specific gravity 1.360). Across the 0.01-0.5 mm thickness range, conveyor speed runs from 0.12-22.96 m/min — thinner sheets move faster, thicker sheets slower, in roughly inverse proportion to thickness. A typical mid-range setpoint is 0.79 m/min for 0.14 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

Design rules for this recipe: hole diameter 15-600 μm, line width 100-500 μm, single-side undercut 2-90 μm — all as a function of thickness across 0.01-0.5 mm. The higher the etch factor (this formula holds about 2.78), the tighter the achievable tolerance. Below the minimum feature sizes, yield falls off steeply, so treat those numbers as hard floors rather than targets.

Yield & Production Economics

Typical mass-production yield for H62 brass in the FeCl₃ system is 97.9%, within an observed range of 97-98.2%. 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

Parts produced with the FeCl₃ formula on H62 brass are common in lead frames, busbars, flexible heater elements, RF gaskets, and precision electrical contacts. 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

This H62 brass formula is part of the standard process library running on our wet chemical etching machine. The same chemistry can be ported to any horizontal spray-etching line of comparable nozzle layout and bath-titration discipline.

For a broader treatment of the material itself — alloy variants, surface preparation, and process limits across thickness ranges — see our Brass chemical etching guide. That overview complements the formula-specific bath and conveyor data on this page.

Production Use Cases for This Formula

Parts produced with this H62 brass + FeCl₃ formula end up in a wide range of finished products. Representative production runs we have completed using this exact recipe family include stainless steel shower-head filter mesh, high-speed air-intake mesh for hair dryers, and stainless steel metal filter mesh. Each case shares the same root sensitivity: clean photoresist edges, a tightly held bath SG of 1.360, and a conveyor speed inside the 0.12-22.96 m/min envelope.

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

The FeCl₃ chemistry is also documented for these alloys.

More Copper & Brass Formulas

Other formulas in the same material family.

Frequently Asked Questions