Overview

A spacer etching service sets a fixed distance between two parts, so the part is only as good as its thickness and its parallelism. A spacer ring that measures 0.80 mm on one side and 0.76 mm on the other tilts whatever it supports, and the error shows up later as a runout or a seal that leaks. Etching handles that by removing metal chemically from both faces at once, leaving a flat, burr-free surface without the shear stress that makes a punched ring dish.

The service side matters as much as the process. A spacer order usually starts as a sketch with a target gap, and it moves through drawing review, a small sample lot, first-article approval and then volume. A supplier set up for that flow will confirm the thickness callout before quoting, cut three to five samples in days rather than weeks, and hold the approved parameters for the production run.

Parameter Window

• Available Materials: stainless steel 304/316L, brass H62, copper, aluminum 5052
• Material Thickness Range: 0.05–1.2 mm
• Tolerance: ±0.02 mm on thickness, ±0.03 mm on outline and concentricity, 0.02 mm parallelism
• Minimum Feature: 0.15 mm hole and 0.2 mm ring wall on 0.1 mm stock
• Surface Options: passivation, degrease and oil-free finish, tarnish inhibitor, anneal for flatness, laser-marked identification
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Drawing Review and Quote — Read the gap the spacer must set, confirm which dimension is functional, and return a quote with the thickness band the process can actually hold.
2. Film and Process Sheet — Plot the artwork and issue a process sheet that fixes alloy, gauge, etch depth and inspection points for that part number.
3. Sample Lot — Etch three to five pieces from the production gauge so the sample carries the same thickness behaviour as the volume order.
4. First-Article Approval — Measure thickness at four points, check parallelism and concentricity, and send the report with the samples for sign-off.
5. Lamination and Exposure — Laminate resist on both faces, expose the ring or plate outline against shared fiducials, and develop.
6. Controlled Etching — Etch through the outline with bath strength, temperature and dwell logged per lot, so thickness loss is a known number rather than a variable.
7. Inspection — Check thickness, flatness, parallelism and edge quality against the approved sample, with a sampling plan agreed at quotation.
8. Packing and Documentation — Pack flat and oil-free, and ship with the inspection report, material certificate and lot number for incoming verification.

Core Advantages

1. Thickness treated as the functional dimension: Gauge is verified on receipt and the etch is timed to a target, so a 0.8 mm spacer arrives at 0.8 mm rather than somewhere inside a loose range.
2. Parallel faces by construction: Both sides are etched in the same bath, so the two faces stay parallel within 0.02 mm without a lapping operation.
3. Samples in days: A spacer etching service cuts samples from production stock, so a design can be trialled in an assembly before a purchase order exists.
4. No tooling cost per revision: A change of inner diameter, wall thickness or tab is a film change, which suits prototype builds and low-volume variants.
5. Burr-free seating: Chemical cutting leaves no roll-over, so the spacer sits flat against a bearing face and does not load one side of the joint.
6. Traceable lots: Each batch carries alloy, gauge, etch record and inspection data, which keeps incoming inspection short and supports RoHS/REACH declarations.

Typical Applications

• Bearing and shaft spacing: Rings that set axial position on 0.5–1.0 mm stainless, held to a parallel thickness.
• Optical lens spacing: Thin brass or aluminum rings that fix the air gap between elements in a barrel.
• Sensor and PCB standoff: Flat plate spacers that set board height without a machined step.
• Valve and pump clearance: Spacers under spring seats where thickness sets cracking pressure.
• Fixture setup: Spacer sets in mixed thicknesses for machine alignment and tool height.
• Display and housing assembly: Thin spacers that take up tolerance between a panel and its frame.

Design Notes & Process Considerations

1. State the functional dimension: Say whether thickness, inner diameter or concentricity controls the fit; the process window is set differently for each.
2. Thickness band, not nominal: Give a band such as 0.80 ±0.02 mm and state whether it applies before or after passivation, since finishing moves the number slightly.
3. Parallelism callout: Ask for 0.02 mm parallelism on spacers that sit under a bearing; without it, the ring can be flat but still tapered.
4. Ring wall minimum: Keep the wall at 0.2 mm or more on 0.1 mm stock; thinner walls etch but deform when the part is pressed into a bore.
5. Edge condition: Specify whether the outer edge should be as-etched or lightly deburred, and note if a sharp edge would damage an O-ring.
6. Sampling plan: Agree the inspection level and the report format at quotation, so first-article approval and volume inspection use the same criteria.