Overview

A leaf spring etching service turns flat metal strip into finished spring parts straight from the drawing, with no dies, no grinding and no tool marks. Photochemical machining laminates a resist onto the strip, exposes it through artwork carrying every beam, slot, contact face and mounting tab, then dissolves the unprotected metal in a matched etchant. A new spring layout costs nothing in tooling and a design revision is simply new artwork. Stock runs from 0.05 mm to 1.2 mm in stainless steel 301/304/316L, beryllium copper C17200, phosphor bronze C5210 and nickel 200.

Springs usually fail at their edges and lose performance to residual stress. A leaf spring etching service removes metal chemically, so edges come out burr-free and free of work hardening, and the temper delivered by the mill survives the process. Stress-relief annealing and forming follow, which keeps force at working deflection inside a ±5% band across the order and leaves the flat blank dimensionally stable. Beams, contact faces and mounting ears all come off one panel, which suits repeat production orders, and every batch ships with force and dimensional records for incoming inspection.

Parameter Window

• Available Materials: stainless steel 301/304/316L, beryllium copper C17200, phosphor bronze C5210, nickel 200
• Material Thickness Range: 0.05–1.2 mm
• Tolerance: outline ±0.05 mm; slot width ±0.02 mm; formed height ±0.10 mm; force at working deflection ±5%
• Minimum Feature: 0.15 mm slot width on 0.15 mm strip; beam width from 0.20 mm
• Surface Options: stress-relief annealing, heat setting, forming and bending, hard gold or nickel plating, passivation, rust-preventive packing
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Order & Drawing Review — Check the flat pattern, slot layout and target force, and agree the forming steps and inspection method up front.
2. Material & Temper Confirmation — Specify stainless, beryllium copper or phosphor bronze with its hardness state, and verify the mill certificate of the incoming strip.
3. Cleaning & Lamination — Degrease the strip and laminate dry film resist under controlled heat and pressure so no bubbles sit under narrow beams.
4. UV Exposure — Expose through artwork registered to the strip edge so pattern position stays consistent across the whole panel.
5. Development — Wash out unexposed resist to open the spring contour, then inspect narrow beams and fine ribs for residual film.
6. Etching — Spray matched chemistry from both sides; line speed and temperature hold slot width and outline inside tolerance.
7. Stress Relief & Forming — Strip and neutralize, then stress-relief anneal, form to shape and heat-set to lock the free height.
8. Final Check & Shipping — Measure outline, slot width, free height and force against the approved sample, then ship on trays or as coil stock with records attached.

Core Advantages

1. No dies, no tool marks: Spring revisions need only new artwork, so tooling cost and press operations disappear and surfaces stay mark-free.
2. Burr-free, stress-free parts: Chemical removal leaves no burr, no hardened rim and no shear-induced stress, so edge strength stays stable.
3. Temper preserved: Incoming hardness state survives etching, so beryllium copper and phosphor bronze deliver their designed elastic behaviour.
4. Consistent force across batches: Identical etch conditions plus stress relief keep force at working deflection inside a ±5% band.
5. Wide thickness and alloy coverage: 0.05–1.2 mm stainless, beryllium copper and phosphor bronze run on one line, so thin and heavy parts share an order.
6. Pattern freedom: A leaf spring etching service carries part numbers, logos and stiffener ribs in the solid land at no extra process cost.

Typical Applications

• Relay armature and contact springs: Flat springs for repeated switching cycles with a narrow force band and long fatigue life.
• Fuse clip springs: Clip springs that hold fuses and protection devices with stable contact pressure.
• Latch and detent springs: Springs with bumps or cut-outs for panel latches, slide detents and door locks.
• Automotive sensor springs: Signal-contact springs built for temperature cycling and vibration in position and temperature sensors.
• Appliance mechanism springs: Return and energy-storage springs for power tools and white goods, supplied in stable repeat volumes.
• Telecom connector springs: Gold-plated contact springs for communication connectors with stable contact resistance over time.

Design Notes & Process Considerations

1. Beam width versus thickness: Keep beam width at about 1.2× material thickness or more; narrower beams lose force stability and deform easily.
2. Set and relaxation: Long-loaded springs need a relaxation allowance on the drawing, with stress relief and heat setting written into the process.
3. Etch compensation: Sidewalls taper roughly half the etch depth per side, so oversize slots and holes in artwork and leave fit allowance.
4. Bend radii: Hold the inside bend radius at or above stock thickness and keep bend lines clear of etched slots to avoid cracking.
5. Plating and contact resistance: Specify nickel plus hard gold on contact faces — burr-free etched surfaces let the deposit build evenly.
6. Surface and packing: A leaf spring etching service delivers mark-free edges and faces, so rust-preventive oil or protective film keeps parts clean in transit.