Ever wonder what goes into building the metal box that houses your electronic device, instrument, or industrial controller? At Pumay Enclosure (Foshan, China), aluminum enclosures go through a precise, multi-stage manufacturing journey — from raw billet to finished product. Here's a behind-the-scenes look at how it all comes together.
Everything starts with the mold. 4 Two primary extrusion mold types are used depending on the enclosure structure:
Mold steel quality is critical. 5 Industry standards recommend using SKD61/H13 (5CrNiMoV) electroslag-remelted steel, with a hardness of 28–32 HRC in the supply state. Sulfur and oxygen content must be ≤0.015%, and ultrasonic testing must meet Grade II or above. 5
After machining the mold, it goes through critical heat treatment steps: quenching at 1020–1040°C, followed by double tempering at 560°C — targeting a final hardness of 46–50 HRC. 5 The mold is then nitrided at 540°C for 6–8 hours, achieving a surface hardness of 1000–1100 HV. 5
The final step before production: trial extrusion and mold adjustment — test extrusions are run and the mold is fine-tuned before being certified for production use. 5
Aluminum extrusion pushes a heated aluminum billet through a die, creating long profiles with consistent shapes — like channels, fins, or tubes.
The most commonly used alloys are 6063-T5/T6 for excellent surface finish and extrudability, and 6061-T6 when higher mechanical strength is required.
Key extrusion tolerances after this stage include 4:
| Parameter | Tolerance Range |
|---|---|
| Overall dimensions (W×H) | ±0.2mm ~ ±0.5mm |
| Wall thickness | ±0.1mm ~ ±0.3mm |
| Diagonal | ±0.3mm ~ ±0.8mm |
| Length | ±0.5mm ~ ±2.0mm |
Once profiles are extruded and cut to length, the real precision work begins.
After extrusion, the profiles are cut to length and further processed with CNC machining to add slots, holes, threads, and assembly features, creating durable and dimensionally consistent enclosures.
Machining tolerance is controllable within ±0.1mm
, meeting the demanding requirements of medical, instrumentation, and industrial automation customers.
Milling, turning, drilling, tapping, and other processes can be completed on a single CNC machine, which avoids positioning errors of traditional step-by-step machining.
Customization options at this stage include 1:
A bare aluminum enclosure is functional, but surface treatment adds protection, aesthetics, and brand identity.
Best options for aluminum enclosures include anodizing, powder coating, brushing, and chemical film (Alodine).
At Pumay, surface treatments are handled by specialized partner factories and include 2:
Anodizing adds corrosion resistance, powder coating provides vibrant finishes, and fluorocarbon coating offers enhanced weather resistance.
The aluminum machining process transforms raw aluminum into finished parts through cutting, milling, turning, and drilling — with CNC machines ensuring precision and efficiency throughout. Post-machining techniques such as deburring, polishing, and surface treatment enhance both aesthetics and functionality.
At Pumay, a dedicated quality inspection team (part of the 35-person production team) verifies dimensional accuracy and surface consistency before every shipment. 3 The factory supports rapid prototyping, standard drawing delivery, and batch assembly — with standard in-stock orders shipping within 2 business days after payment confirmation. 1
Pumay's core capabilities include: aluminum extruded enclosures, waterproof enclosures, 19-inch rackmount chassis, and CNC custom parts — supporting both small-batch customization and mass production via OEM/ODM services.
Whether you're an R&D engineer needing a prototype in days, a manufacturer sourcing in bulk, or a defense organization demanding high IP ratings, understanding this process helps you ask the right questions — and choose the right supplier.
Have a project in mind? Contact Jessie at jessie@pumay-aluminum.com or visit www.pumay-aluminum.com to get started.
