6061 Aluminum Nested Mold Fixture with Multi-Level Pockets Machined to 0.01mm Pocket Depth for Stepped Inserts

This nested mold fixture holds a stepped insert stack in three descending pockets so the inserts seat on machined floors rather than on each other. The depth of every level is what sets the stack height: 0.02 mm of error at the first pocket turns into a visible mismatch at the top surface, and no amount of clamping pressure removes it. We cut all three levels in one clamping from a 6061-T6 plate, so each floor is referenced to the same base plane.

The fixture also carries reamed dowel holes for locating the insert set and threaded holes for clamping. Dowel holes are reamed to H7 after the pockets are finished, which keeps pin position within 0.01 mm of the pocket centre and stops the insert from being pulled sideways when the clamps are tightened.

1. Drawing review. We check pocket depth per level, step heights, wall thickness, dowel positions and clamp clearance, then return a marked drawing and quotation within one working day.
2. Material check. 6061-T6 plate is verified against the mill certificate for temper and flatness before it is cut.
3. Stress relief and facing. The blank is stress relieved and both faces are faced, establishing the base datum that every pocket depth is measured from.
4. Roughing the levels. Each pocket level is roughed with 0.4 mm stock left on floors and walls, working from the largest pocket inward so the part keeps its rigidity.
5. Finishing top-down. Levels are finished from the top down in one clamping, so the tool always reaches the floor without the wall of an outer pocket deflecting the cutter.
6. Dowel holes and threads. Dowel holes are drilled, bored and reamed to H7; threaded holes are cut and checked for depth so a screw cannot bottom and lift the insert.
7. Deburr and anodizing. Pocket edges are broken, the part is cleaned, and clear or black anodizing is applied with pocket floors and dowel holes masked to protect the fit.
8. Inspection. CMM for every floor height and dowel position, pin gauges for the reamed holes, depth micrometer cross-check, then a first article report with the batch.

When a deep outer pocket is finished first, the remaining wall is thin and the finishing cutter pushes it outward, so the wall ends up tapered and the next level is referenced to a surface that has already moved. Finishing from the top down keeps a full section of material behind every wall until its own pass is complete. We also use a smaller step-over on the final wall pass and a sharp cutter, because a worn tool leaves a rub mark that shows through anodizing and tells the customer the fixture was rushed.

Pocket count, level depths, insert footprints, dowel pattern, clamp holes and base size are all built to your drawing. A single fixture is a normal order with no tooling charge and no setup fee, and the prototype is machined with the same programme and inspection plan as a batch. Where a design cannot be machined as drawn, our engineer returns a DFM note with a practical alternative and waits for written approval before cutting metal.

• NDA before files. Mutual non-disclosure is signed before drawings, models or samples are released, covering geometry, volume, end use and customer identity.
• No reference use. Confidential fixtures never appear as samples, catalogue items, website photos or trade show parts; photos need written release.
• Separated cell. Sensitive work runs in a designated area with named operators, and programmes and fixtures are stored under a project code.
• Controlled partners. Anodizing suppliers receive the process specification only, never the assembly drawing.

Dongguan Changxinda Precision Technology Co., Ltd has been machining custom parts since 2008. We run four-axis and five-axis machining centres, turn-mill lathes, CNC lathes and milling machines with 90 to 102 staff and an ISO 9001:2015 system. More than 200 customers are served, 50 to 60 percent of output is exported, and annual sales are between USD 10 million and 20 million. Each custom project has a named engineer, each batch ships with a first article report, and each date is confirmed before the order is accepted.

• Dates in writing. Prototypes 5 to 8 working days, batch orders 15 to 25 working days after drawing approval.
• Repeat orders skip setup. Programmes, fixtures and gauge sets stay on file, so a repeat starts in production.
• Reserved slots. Blanket orders are booked into fixed monthly machine time, keeping the same part arriving in the same week.
• Early notice. If material, anodizing or capacity threatens the date, you hear it before the date is missed, with a partial shipment offered.
• Dispatch evidence. Photos, inspection report and packing list before shipment; tracking number on the day of dispatch.

• Consumer Electronics: phone, tablet and laptop housings, heat sinks, camera brackets, VR/AR headset structural parts, smart wearable shells
• Automation & Industrial Equipment: automation fixtures, jigs, module frames, transmission sliders, motor mounts, sensor housings, conveyor line parts
• Semiconductor & Vacuum Equipment: vacuum chambers, vacuum fittings, precision equipment bases, thermal isolation and insulation parts, inspection fixtures
• Medical Devices: surgical instrument bases, diagnostic instrument housings, endoscope components, aesthetic device structural parts (medical-grade aluminum and stainless steel)
• Automotive: new energy motor housings, battery end plates, sensor brackets, lamp structural parts, tuning parts, hydraulic valve blocks
• Aerospace & UAV: aircraft structural parts, drone frames, landing gear parts, avionics instrument housings (lightweight precision parts)
• Optics & Photonics: optical lens barrels, lens mounts, light source heat sinks, camera module brackets, inspection optical benches
• Communications: 5G heat dissipation cavities, filter parts, signal adapter structural parts, telecom equipment housings
• Robotics: robot arm joint parts, robot bases, reducer housings, AGV structural parts
• Instrumentation: test equipment housings, precision gauge bases, flow meter parts, laboratory equipment accessories

Each fixture is bagged with desiccant, separated by EPE foam so pocket floors and dowel holes cannot be bruised, and packed in a five-layer export carton marked with part number, quantity and batch code. Sea freight goes on a fumigation-free plywood pallet; air freight uses a reinforced carton with edge protectors. Neutral packing is available.