Carbon & Tool Steel FeCl₃+HCl

Chemical Etching Formula
SKS3 Alloy Tool Steel with FeCl₃+HCl

For engineers selecting an etching chemistry for SKS3 Alloy Tool Steel, the FeCl₃+HCl formula shown here defines the bath composition, temperature window, and achievable feature sizes across a 0.1-0.5 mm thickness band. Typical mass-production yield for this recipe is 96.3%, with a typical conveyor speed of 0.27 m/min at 50°C.

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.

FeCl₃+HCl Etchant System
44 °Bé Concentration
1.410 Specific Gravity
50 °C Bath Temperature
Through etch (double-sided) Etch Depth Type
0.1-0.5 mm Thickness Range
0.25 mm Typical Thickness
0.12-0.98 m/min Conveyor Speed Range
0.27 m/min Typical Speed
120-600 μm Min Hole Ø Range
100-500 μm Min Line Width Range
19-94 μm Undercut Range
2.65 Etch Factor (EF)
96.3% Typical Yield (95.5-96.7%)

Why FeCl₃+HCl for SKS3 Alloy Tool Steel?

Ferric-chloride-based formulas are the industrial workhorse for ferrous, nickel, and copper-bearing alloys like SKS3 Alloy Tool Steel. The Fe³⁺ ion oxidizes the metal surface; where HCl is present it regenerates dissolved species and stabilizes chloride concentration. The result on SKS3 Alloy Tool Steel is anisotropic etching with predictable undercut and an easily regenerated spent bath.

Process Window & Bath Control

Bath control for SKS3 Alloy Tool Steel in FeCl₃+HCl: temperature 50°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 0.12-0.98 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 120-600 μm and the minimum line width ranges 100-500 μm across the 0.1-0.5 mm band, following the industry 1.2× (hole) and 1.0× (line) thickness rules. Single-side undercut ranges 19-94 μm, and the etch factor is about 2.65. Size your photomask by subtracting twice the expected undercut from each finished feature dimension.

Design Rule Summary
• Minimum hole diameter range: 120-600 μm
• Minimum line width range: 100-500 μm
• Single-side undercut range: 19-94 μm
• Typical etch factor (EF): 2.65

Yield & Production Economics

This formula delivers a typical yield of 96.3% (range 95.5-96.7%). 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 SKS3 Alloy Tool 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.

More Carbon & Tool Steel Formulas

Other formulas in the same material family.

50CrV4 Spring Steel FeCl₃+HCl Through etch (double-sided) 65Mn Spring Steel FeCl₃+HCl Through etch (double-sided) 65Mn Spring Steel FeCl₃+HCl Half etch (single-sided) DT4 pure iron FeCl₃+HCl Through etch (double-sided) SK2 Tool Steel FeCl₃+HCl Through etch (double-sided) SK3 Tool Steel FeCl₃+HCl Through etch (double-sided)

Frequently Asked Questions

The recommended working concentration for SKS3 Alloy Tool Steel in the FeCl₃+HCl system is 44 °Bé, corresponding to a specific gravity of about 1.410. Titrate the bath at least once per shift and correct back toward this setpoint; drift below it signals depletion, while drift above usually means evaporative water loss.

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.

Request a Quote Browse Formulas