Chemical Etching Formula
65Mn Spring Steel
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 65Mn Spring Steel?
On 65Mn Spring Steel, 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 65Mn Spring Steel etch line runs a variant of this formula.
Process Window & Bath Control
Bath control for 65Mn Spring Steel in FeCl₃+HCl: temperature 48°C, concentration 44 °Bé, specific gravity 1.410. The recipe is tuned for half etch (single-sided). Conveyor speed is the primary throughput control, ranging 47.73 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 65Mn Spring Steel at half etch (single-sided), plan for a minimum hole diameter in the 10 μm range and a minimum line width in the 100 μm range, depending on the chosen sheet thickness within 0.01 mm. The etch factor of ~2.72 and undercut range of 1 μm determine how much the mask must be biased to land the finished dimension on target.
• Minimum hole diameter range: 10 μm
• Minimum line width range: 100 μm
• Single-side undercut range: 1 μm
• Typical etch factor (EF): 2.72
Yield & Production Economics
This formula delivers a typical yield of 97.4% (range 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
Typical applications for 65Mn Spring Steel processed with FeCl₃+HCl include spring elements, blades, shim stock, and stamped-replacement flat parts. The formula's tolerance band and yield make it well suited to medium-to-high-volume precision flat parts.
Process Equipment & Material Reference
On the shop floor, this 65Mn Spring Steel + FeCl₃+HCl recipe is implemented on a plasma surface treatment machine. The 48°C bath setpoint and 47.73 m/min conveyor range correspond to verified production envelopes on that equipment for half etch (single-sided).
If you need a wider view of steel beyond this single recipe, our 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
Typical end-uses for 65Mn Spring Steel run on this formula include mobile-phone earpiece mesh, custom thin-film heating elements, and electronic thin-film component etching. The 48°C bath and 0.01 mm supported thickness range cover most of the production work in these segments without re-tuning chemistry.
Designs that sit slightly outside this thickness or feature-size envelope are usually addressable by a sister formula in the same etchant family. The bath chemistry stays the same; the tuning shifts to conveyor speed and resist choice.
More Carbon & Tool Steel Formulas
Other formulas in the same material family.
Frequently Asked Questions
Sources & References
- ASTM E407: Standard Practice for Microetching Metals and Alloys
- ASTM B912: Standard Specification for Passivation of Stainless Steels
- Photo Chemical Machining Institute — process capability guidelines
- NIST Engineering Statistics Handbook — process tolerance and capability
Standards are referenced for context. Always confirm parameters against the current published edition and your own process validation.
Need a Quote for This Process?
WET Etched runs production wet chemical etching lines using the FeCl₃+HCl chemistry. Send us your part drawing and quantity for a full process quote.