Most latch failures are not broken parts, they are lost preload. A friction clamp depends on a screw staying at a torque it cannot hold under vibration; an over-centre lever depends on geometry, but only if the pin bore and the striker engagement are machined to the right numbers. A pin fit of 0.05 mm gives the lever 0.05 mm of slop, and the pack walks.

This latch is machined with the pin bore reamed to H7 Ø6 so the fit is 0.01 mm, the striker engagement held to ±0.05 mm, and the spring pocket depth controlled so preload does not fade. Every latch is cycled on a test fixture before the batch ships, and the locked position is measured again after the cycling.

• Geometry, not friction — over-centre lever keeps the pack clamped without screw torque.
• 0.01 mm pin fit — no lever slop, so the locked position repeats within 0.02 mm.
• Preload that survives — spring pocket depth ±0.05 mm, verified after cycling.
• Wear faces protected — 25 µm hard anodizing with the pin bore masked and faces polished.

1. Pack and kinematics review — battery footprint, CG position, latch travel and release force confirmed before machining.
2. Material verification — 7075-T6 received by heat number with ultrasonic check and 3.1 material certificate.
3. Rough machining — lever blank, body and striker roughed with 0.5 mm allowance.
4. First stress relief — low-temperature relief so the thin lever arm does not bend after release.
5. Semi-finish — body cavity, spring pocket and striker face semi-finished.
6. Second stress relief — a second cycle before the pin bore is finished.
7. Pin bore and assembly — Ø6 bore reamed to H7, lever fitted and cycled on a fixture, locked position recorded.
8. Hard anodizing — 25 µm on body and striker, pin bore and wear faces masked, faces polished after coating.
9. Cycle test and verification — 1000 release cycles, locked position re-measured, CMM report and FAI shipped.

• Actuation — single-hand over-centre, push-button, or a slide latch with a detent ball.
• Holding force — tuned through spring rate and lever ratio from 50 N to 400 N.
• Mounting — screw bosses, bonded pads, or a clamped rail with anti-rotation pins.
• Material — 7075-T6 body, stainless striker and pin for marine or high-cycle duty.
• Sampling — 1 pair fitted to your tray for a drop and vibration trial.

Motor geometry, stator stack and winding data are competitive information, so access is limited from the drawing stage onward.

• NDA first — mutual NDA and non-circumvention signed before any file is exchanged.
• Isolated area — dedicated machines and authorized staff, no phones or photography inside.
• Codified routing — internal codes on travelers and labels instead of your part numbers.
• Data control — per-project folders on a permission server, destroyed on request with a record.
• No display — no drawings, part photos or logos in samples, catalogs, the website or social media.

Dongguan Changxinda Precision Technology Co., Ltd. — founded in 2008, 90-102 staff, ISO 9001:2015 certified, annual sales USD 10-20 million, export share 50-60%, serving customers in Europe, North America, Japan and Southeast Asia.

Machining, stress relief, anodizing and metrology run in one plant: 5-axis and 4-axis machining centers, turn-mill centers, surface grinders, wire EDM, CMM, 2.5D vision metrology and automated anodizing lines. About 12,000 aluminum parts ship each month, most of them small precision parts where the fixture and the boring sequence decide the result.

1. 01 Consumer Electronics — Phone, tablet and laptop housings · heat sinks · camera brackets · VR/AR headset structural parts · smart wearable housings
2. 02 Automation & Industrial Equipment — Automation jigs · fixtures · module frames · transmission sliders · motor mounts · sensor housings · conveyor line components
3. 03 Semiconductor & Vacuum Equipment — Vacuum chambers · vacuum fittings · semiconductor equipment precision bases · thermal insulation parts · inspection fixtures
4. 04 Medical Devices — Surgical instrument bases · medical device housings · endoscope components · aesthetic equipment structural parts (medical grade aluminum / stainless steel)
5. 05 Automotive — EV motor housings · battery end plates · sensor brackets · lamp structural parts · aftermarket parts · hydraulic valve blocks
6. 06 Aerospace & UAV — Aircraft structural parts · UAV frames · landing gear components · avionics instrument housings (lightweight precision parts)
7. 07 Optics & Photonics — Optical lens barrels · lens mounts · light source heat sinks · camera module brackets · inspection optical stages
8. 08 Telecommunications — 5G heat sink cavities · filter housings · signal adapter brackets · telecom equipment enclosures
9. 09 Robotics — Robotic arm joint parts · robot bases · reducer housings · AGV chassis structural parts
10. 10 Instruments & Meters — Inspection equipment housings · precision gauge bases · flow meter parts · laboratory equipment components

Two shifts 07:30-22:00, six days a week, with weekend shifts in peak season. Capacity is locked weekly for volume programs, so a rush order never displaces a scheduled batch.

• Samples — 7-10 days, checked on your stator or bearing set before the batch is released.
• Batch — 15-20 days from deposit and drawing approval.
• Buffer stock — semi-finished stock for repeat models, cutting repeat lead time by about 30%.
• Shipping — DHL/FedEx/UPS in 3-5 days for samples; air or sea for volume; EXW Dongguan, FOB Shenzhen or CIF.
• Documents — FAI, 3.1 material certificate, CMM report and packing list with every shipment.

Send STEP / IGES / DWG / PDF and receive DFM feedback plus a formal quotation within 24 hours.

Dongguan Changxinda Precision Technology Co., Ltd. · ISO 9001:2015 · Dongguan, Guangdong, China