Overview

A washer etching service forms inner and outer profiles by dissolving metal through a photoresist mask instead of punching it with a die. The strip is laminated, exposed through film carrying the washer geometry, developed, and etched from both faces at once, so the bore and the outside diameter are generated in the same pass with no roll-over, no shear burr and no die mark. Parts leave the line flat, with straight walls and a wall thickness that stays even around the full circumference. Stock is normally stainless steel 304/316L, spring steel 301, copper, brass or aluminum between 0.05 mm and 2.0 mm, held to ±0.05 mm on bore and outside diameter.

Because nothing is cut with hard tooling, the service is built around response rather than die lead time. A quote is issued against drawings within one working day, the first-article sample is etched from the same film set that will run production, and volume then scales on the same line with no tooling amortisation step. That rhythm fits maintenance spares, prototype builds and multi-size kits, where the quantity per size is small but the number of sizes in one order is large.

Parameter Window

• Available Materials: stainless steel 304/316L, spring steel 301, copper C110, brass H62, aluminum 5052
• Material Thickness Range: 0.05–2.0 mm
• Tolerance: ±0.05 mm on bore and outside diameter, ±0.01 mm on strip thickness as supplied
• Minimum Feature: 0.3 mm bore, 0.2 mm slot and 0.15 mm wall at 0.3 mm stock
• Surface Options: as-etched matte, passivation, electropolishing, nickel plating, black oxide, tumbled edge break
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. RFQ & Drawing Review — Check bore, outside diameter, wall and flatness against the quoted thickness, and return a costed reply inside one working day.
2. Material & Temper Match — Select alloy and temper for the load case, then confirm strip flatness and surface condition before release.
3. Film Set & Sample Run — Generate the exposure film from the drawing and etch a small first-article lot so fit can be checked before batch release.
4. Cleaning & Lamination — Degrease both faces and laminate dry film resist under controlled heat and pressure so no bubble sits over the bore edge.
5. Exposure & Registration — Expose both sides through registered film, keeping bore and outside diameter concentric to within the drawing callout.
6. Development — Wash out unexposed resist and inspect the open areas for residue that would block etching at the bore wall.
7. Etching — Etch from both faces in chemistry matched to the alloy; time, temperature and conveyor speed set wall straightness and thickness loss.
8. Finishing & Release — Strip resist, neutralise, apply the specified finish, then verify bore, wall, flatness and burr before packing by size.

Core Advantages

1. Bore and OD in one pass: Both profiles etch simultaneously, so concentricity does not depend on two separate punching operations or on die wear between them.
2. No tooling charge: A new size is a new film, not a new die, so a kit of twenty diameters can be quoted, sampled and shipped without amortising twenty tools.
3. Burr-free on both faces: Chemical removal leaves no shear burr, so washers sit flat under a screw head and do not damage plated or painted mating surfaces.
4. Repeatable thickness: Thickness comes from the strip, not from the process, so a 0.5 mm washer stays 0.5 mm batch after batch and stack height stays predictable.
5. Fast sampling loop: Sample and production run on the same film set, so what is approved at first article is what arrives in the batch.
6. Mixed-size orders: Different diameters and materials share one sheet or one coil, letting a single purchase order cover a full service kit. A washer etching service therefore removes the minimum-order problem that stamping carries.

Typical Applications

• Sealing washers: Flat sealing rings for hydraulic and pneumatic fittings, etched in 0.8 mm copper or soft stainless.
• Insulating washers: Shoulder-free insulating rings for terminal and busbar isolation, cut in 0.3 mm aluminum or brass.
• Thrust washers: Wear rings between rotating faces, produced in 0.5 mm spring steel 301 with a polished face.
• Adjustment washers: Thin shim-type washers used to set preload and end play in gearboxes and bearings.
• Filter support washers: Perforated backing rings that support filter media without blocking flow area.
• Retaining and cover washers: Flat cover rings for sensor ports and small motor housings, supplied deburred and passivated.

Design Notes & Process Considerations

1. Wall thickness rule: Keep the narrowest wall at 1.0 × material thickness or 0.15 mm, whichever is larger, or the bore edge will etch thin on one side.
2. Tolerance split: State bore and outside diameter separately; a ±0.05 mm callout on both is achievable, but a total wall tolerance tighter than 0.08 mm needs review.
3. Burr and edge condition: Etched washers have straight walls by default; ask for a tumbled edge break only where handling sharpness matters.
4. Temper and flatness: Spring temper improves flatness after etching but is harder to flatten afterwards, so specify flatness per 100 mm up front.
5. Material marking: Mixed-size sheets need a laser or ink mark outside the part outline, otherwise sorting after etching becomes a manual step.
6. Order structure: Give annual quantity, size count and reorder pattern in the RFQ. The response, sampling and batch flow of a washer etching service is planned around that pattern, not around a single line item.