Overview

Razor blade chemical etching shapes the cutting edge of a blade from martensitic stainless 420 or 440A sheet, 0.10–0.30 mm thick, by dissolving metal to a controlled half-etch depth rather than grinding it away. A resist mask protects the body of the blade while the edge land is thinned to roughly 0.01–0.03 mm, leaving a continuous, burr-free bevel on both faces at a defined included angle. Because every blade on a sheet sees the same chemistry and time, edge geometry repeats from piece to piece, and the unetched spine keeps the strip rigid enough for downstream coating and assembly. The result is a keen, uniform edge with no grinding marks or heat tint.

The edge is a half-etch problem more than a cutting problem. Etch depth, sidewall angle and spray pressure decide the final land thickness, and the artwork is compensated so the dissolved amount, not the film line, sets the edge. Parts are usually left on a carrier frame through stripping, then hardened, coated with platinum-chromium, DLC or PTFE, and singulated. Razor blade chemical etching is chosen when a blade needs a very thin, consistent edge across a high-volume strip, and where mechanical grinding would introduce burrs, variability or a heat-affected zone.

Parameter Window

• Available Materials: martensitic stainless 420/440A/440C, 13Cr stainless, hardened and tempered strip
• Material Thickness Range: 0.10–0.30 mm, with 0.15–0.20 mm the common blade gauge
• Tolerance: ±0.01 mm on edge-land thickness, ±0.02 mm on profile, half-etch depth ±0.01 mm
• Minimum Feature: 0.01–0.03 mm edge land, 15–25 degree included bevel, 0.3 mm minimum spine width
• Surface Options: bare, PtCr coating, DLC, PTFE, electropolished, carrier-frame delivery
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Edge Geometry Review — Set land thickness, bevel angle and half-etch depth from the cutting target, then build the compensated artwork.
2. Strip Selection — Choose alloy and hardness, and verify thickness uniformity, since gauge variation becomes edge variation.
3. Cleaning & Lamination — Laminate dry film on both faces, keeping the edge zone free of bubbles that would round the bevel.
4. Dual-Side Exposure — Expose front and back edge-band artwork in register, leaving the spine and carrier frame fully protected.
5. Development — Develop both faces and inspect the narrow edge band, where any scum produces a thick, blunt land.
6. Half-Etch Edging — Spray ferric chloride at fixed Baume and temperature to thin the edge band to the set land thickness and angle.
7. Stripping & Hardening — Strip resist, then harden and temper, and apply PtCr, DLC or PTFE coating to the finished edge.
8. Singulation & Inspection — Cut blades from the carrier frame, then measure land thickness, bevel angle and edge continuity against the sample.

Core Advantages

1. Burr-free edge: Chemical thinning leaves no grinding burr, so the edge is clean and comfortable against skin.
2. Consistent land: All blades on a sheet reach the same 0.01–0.03 mm land, so sharpness does not vary across a batch.
3. No thermal damage: No grinding heat means no temper loss or heat tint at the thinnest section of the edge.
4. Controlled bevel: Etch depth and spray angle set the included bevel reproducibly, without a grinding wheel that wears.
5. Rigid carrier frame: The unetched spine holds the strip flat through coating and handling, so thin edges do not fold.
6. High-volume uniformity: A controlled razor blade chemical etching line repeats the same edge geometry on every blade of a long strip.

Typical Applications

• Wet-shave blades: Thin half-etched edges for cartridge and double-edge razor blades, coated with PtCr and PTFE.
• Medical and surgical blades: Fine scalpel and microtome edges where a burr-free bevel is required.
• Industrial slitting knives: Small precision blades for film, foil and tape converting equipment.
• Food and fibre cutters: Thin stainless edges for slicing and chopping assemblies, hardened after etching.
• Safety and utility blades: Shaped blades with slots and mounting holes etched in the same pass as the edge.
• Sample preparation blades: Consistent edges for laboratory sectioning and histology consumables.

Design Notes & Process Considerations

1. Land from cut target: Fix edge-land thickness and bevel angle from the required cutting force first, then set half-etch depth.
2. Gauge control: Hold incoming strip thickness tightly, because a ±0.01 mm gauge error shifts the finished land by the same amount.
3. Sidewall compensation: State the etch factor for the edge band and offset the artwork so the bevel lands where the drawing wants it.
4. Spine width: Keep a rigid unetched spine and carrier frame, or the 0.02 mm edge will warp during coating.
5. Coating allowance: Reserve land thickness for PtCr or DLC build-up, since a thick coating rounds a very fine edge.
6. Edge inspection: Require a land-thickness measurement and continuity check on sampled blades, not just a visual sharpness test.