Instrument and control enclosures
Panel-mount and wall-mount boxes for controllers, drives and measurement instruments, usually with a machined lid land, a cast gasket groove and a cosmetic powder coated finish.
Die cast aluminum enclosures
Die Cast Aluminum Enclosures
A die cast aluminum enclosure is a sealed metal box that protects and shields electronics, typically with a cast gasket groove, cable gland bosses and PCB mounting standoffs. CharMax Precision casts enclosures in A360, ADC12 and A380 aluminum from 0.1 to 8 kg, machining lid lands and gland holes so the assembled unit reaches IP65 or IP67.
In short
A die cast aluminum enclosure is a sealed metal box that protects and shields electronics, typically with a cast gasket groove, cable gland bosses and PCB mounting standoffs. CharMax Precision casts enclosures in A360, ADC12 and A380 aluminum from 0.1 to 8 kg, machining lid lands and gland holes so the assembled unit reaches IP65 or IP67.
Aluminum earns its place over moulded plastic on two counts. It shields, because a cast aluminum wall is inherently conductive and passes EMC emissions and immunity testing without the conductive paint, foil liner or plated coating a plastic box needs. And it conducts, because at 96 to 121 W/m·K the enclosure wall becomes the heat path for the electronics inside, which often removes a separate heat sink and sometimes a fan from the bill of materials.
An enclosure is a sealing problem rather than a load-carrying problem, and the design rules follow from that. If the part you are sourcing carries mechanical load or locates a bearing, shaft, gear or impeller, that is a structural housing, and the Aluminum Die Cast Housings page linked below covers bore concentricity, sealing faces and pressure tightness instead.
Capability at a glance
| Typical parts | Instrument enclosures, control and junction boxes, telecoms and sensor housings |
|---|---|
| Preferred alloys | A360 for corrosion resistance, ADC12 for thin walls |
| Ingress protection | IP65 and IP67 achievable, IP68 case by case |
| Part weight | 0.1 to 8 kg per enclosure or lid |
| Wall thickness | 2 to 3 mm typical, 1.5 mm on small enclosures |
| Gasket groove | 1.5 to 3 mm wide, cast with 2 to 3° draft on both flanks |
| Lid land flatness | 0.05 mm per 100 mm after machining |
| Fastener spacing | 40 to 70 mm for even gasket compression |
| EMI shielding | Inherent to the alloy, no conductive coating needed |
| Standard finishes | Shot blast, powder coat to RAL or Pantone, chromate conversion |
| Annual volume | 500 to 500,000+ parts |
| Lead times | 25-40 days tooling, 15-25 days production |
What a die cast aluminum enclosure is
An enclosure is a sealed box built around a circuit board, a terminal block, a display or a sensor. Its job is to keep water and dust out, keep electromagnetic interference in or out, give the electronics somewhere solid to mount, and in many cases carry the heat those electronics generate out to the ambient air. Almost every dimension on the drawing traces back to one of those four functions.
Most enclosures are a two-piece set: a base and a lid, cast in separate dies, machined as a pair, and often shipped assembled with the gasket already fitted. The gasket groove is cast into one half, the mating land is machined on both, and the fastener pattern is chosen so the gasket compresses evenly rather than only near the screws.
Aluminum is chosen over plastic when shielding, heat, mechanical robustness or a metal appearance matter, and over sheet metal fabrication when the design needs cast-in features. A cast enclosure arrives with its gasket groove, PCB standoffs, gland bosses, DIN rail features, drip lips and mounting lugs already formed, none of which a folded sheet metal box can produce without added parts and operations.
Junction and terminal boxes
Multi-entry boxes with several cable gland bosses cast into the walls, an internal earth bonding boss and DIN rail mounting features cast into the base.
IP-rated outdoor enclosures
Weather-exposed boxes cast in A360 with drip lips, sloped upper surfaces, a breather vent boss and a stainless fastener set, tested to IP65 or IP67 before shipment.
Telecoms and networking housings
Remote radio, small cell and outdoor gateway housings that combine a sealed internal cavity with external cast fins, so the same casting is both enclosure and heat sink.
Sensor and camera enclosures
Small, thin-wall enclosures where a window or lens aperture has to be machined concentric with an internal mount, often in ADC12 because of the wall thickness involved.
Two-part enclosure sets
Base and lid quoted, tooled and inspected as a matched pair, with the gasket, inserts and hardware fitted in-house so the customer receives a sealed unit rather than components.
Enclosure or housing: which part do you actually need?
These two part families overlap in language but not in engineering. An enclosure is dimensioned around a seal, a housing is dimensioned around a bearing. Everything else follows from that difference, including alloy, wall thickness, which faces get machined and which test proves the part is good.
An enclosure is judged on ingress protection and shielding. The dimensions that matter are gasket groove depth and width, lid land flatness across the whole perimeter, fastener spacing, gland hole diameter and the continuity of the seal path. A housing is judged on load and leakage under pressure. The dimensions that matter are bore diameter and concentricity, bore-to-bore centre distance, shaft centreline height and sealing face flatness.
Use the table below to place your part. If the answer keeps landing in the right-hand column, the Aluminum Die Cast Housings page in the related links below is the one to read. Parts that are genuinely both, such as a motor drive with a sealed electronics bay, get both rule sets applied to the relevant regions.
| Question | Choose an enclosure | Choose a housing |
|---|---|---|
| What sits inside the part? | A PCB, terminal block, display or sensor | A shaft, bearing, gear, impeller or piston |
| What is the part resisting? | Water, dust, salt spray and electromagnetic interference | Mechanical load, working pressure and vibration |
| Which dimension is critical? | Gasket groove depth and lid land flatness | Bore diameter and bore-to-bore centre distance |
| How is the seal made? | A continuous gasket compressed by evenly spaced screws | Shaft seals and O-rings in a pressure-tight cast wall |
| What sets the wall thickness? | Filling, shielding and lid stiffness, 2 to 3 mm | Stiffness under load, 2.5 to 4 mm |
| Which test proves it works? | IP65 or IP67 ingress test and an EMC scan | Leak test at working pressure and a CMM bore report |
| Which alloy is usual? | A360 outdoors, ADC12 for thin walls | A380 for machinability, A360 for pressure tightness |
| What does the finish have to do? | Look right and match a colour reference | Protect against corrosion and hold paint |
Alloy options for die cast aluminum enclosures
A360 is the default for anything mounted outdoors, washed down or exposed to salt. Its copper content is capped at 0.6% against 3 to 4% in A380, and copper is the element that drives galvanic corrosion in aluminum, so an A360 enclosure survives humidity and salt spray testing far better for a few percent more on the alloy cost. A360 is also rated excellent for pressure tightness, which matters when an IP67 claim depends on the wall itself being sound rather than only on the gasket.
ADC12 is specified where the enclosure is thin walled or the metal has a long way to travel from the gate, which is the usual situation with a shallow, wide lid. Its 9.6 to 12% silicon improves fluidity into 1.5 to 2 mm sections. A380 remains the cheapest grade and is the right answer for an indoor enclosure inside a cabinet, particularly one that needs a lot of machining.
Where the enclosure also has to move heat, A360 at 113 W/m·K or A413 at 121 W/m·K conduct meaningfully better than A380 and ADC12 at 96 W/m·K. That spread of roughly 26% is worth taking when it is free, but fin area, air path and the quality of the interface to the heat source all matter more than the alloy figure.
| Requirement | Alloy | Reason |
|---|---|---|
| Outdoor, marine or wash-down service | A360 | 0.6% maximum copper gives materially better corrosion resistance |
| IP67 where the wall itself must be sound | A360 | Rated excellent for pressure tightness, fewer through-wall leak paths |
| Walls at or below 2 mm | ADC12 | 9.6 to 12% silicon improves fluidity into long, thin sections |
| Indoor enclosure at the lowest cost | A380 | Lowest alloy cost and the best machinability of the group |
| Enclosure that also dissipates heat | A360 or A413 | 113 and 121 W/m·K against 96 W/m·K for A380 and ADC12 |
| Painted cosmetic finish | A360 preferred | Lower copper reduces corrosion creeping under paint at machined edges |
Anodizing is possible on all four grades but produces a darker, less uniform finish than on wrought aluminum because of the silicon content. Powder coating is the usual choice for a controlled colour.
Sealing and IP ratings on cast aluminum enclosures
An IP rating belongs to the assembled enclosure, not to the casting. The rating is delivered by four things acting together: the cast gasket groove, the flatness of the two lands that close on the gasket, the fastener pattern that compresses it, and the glands and connectors that penetrate the wall. A perfect casting with an under-specified gland will still fail the test.
The practical dividing line sits between IP54 and IP65. Up to IP54 an as-cast land with a foam gasket is usually enough. From IP65 upward the land has to be machined, because as-cast flatness of 0.1 mm per 100 mm becomes 0.2 mm or more of gap across a 200 mm lid, and no gasket recovers that unevenly. Machining the land to 0.05 mm per 100 mm is a single milling pass and it is what makes the rating repeatable in production rather than only on the sample.
Coating thickness has to be accounted for in the sealing calculation. Powder coat at 60 to 90 µm on a gasket land changes compression noticeably on a shallow groove, so lands are either masked before coating or the groove depth is adjusted for the coating that will sit in it. That decision is made at drawing stage, not at first article.
| Rating | What it means | What the design needs |
|---|---|---|
| IP54 | Dust protected, resists splashing water | Cast groove with a foam or sponge gasket, as-cast land is acceptable |
| IP65 | Dust tight, resists water jets | Machined land, moulded or cast-in-place gasket, glands rated to match |
| IP66 | Dust tight, resists powerful water jets | Machined land, stiffened or flanged lid, fasteners at 40 to 60 mm spacing |
| IP67 | Dust tight, 30 minutes immersed at 1 m | Land machined to 0.05 mm per 100 mm, pressure-tight A360 casting, breather vent |
| IP68 | Continuous immersion deeper than 1 m | Case by case, normally needs vacuum-assisted casting and a bonded or double seal |
| IP69K | High pressure, high temperature wash-down | Not typical for a cast enclosure, discuss before the design is frozen |
We can ingress or leak test to the rating stated on your drawing before shipment, and issue the test record with the lot. Tell us the rating early, because it changes the machining scope and the finishing sequence.
How a die cast enclosure is manufactured, cast versus machined
The gasket groove is cast, not machined. Once it is in the die it costs nothing per part, whereas machining a groove adds a slow contouring pass to every unit. What does get machined is the flat land on either side of the groove, along with the matching land on the lid, because gasket compression depends on the two faces closing evenly along the whole perimeter.
Die design concentrates on two things: filling the shallow, wide sections of a lid before the metal freezes, and holding the groove geometry as the die wears. The groove is a thin standing rib of steel in the die, so it runs hotter than the surrounding block and is the first feature to show heat checking. Cooling is routed close to it and the groove is inspected at agreed shot intervals through the tool life.
After casting, parts are trimmed, deburred and shot blasted. Mating lands are milled, gland and connector holes are drilled and reamed, bosses are tapped, and the earth bonding face is masked. The set is then powder coated, the gasket is fitted, inserts are installed, bonding continuity is checked, and the assembly is ingress tested before packing.
- Cast: gasket groove profile, PCB standoffs, cable gland bosses, DIN rail features, internal ribs, external mounting lugs, breather boss, cast-in labels and rating text
- Cast: hinge and latch bosses, drip lips and rain shields on outdoor enclosures, and 0.5 to 1.0 mm of machining stock on both mating lands
- Machined: the base and lid mating lands, to 0.05 mm per 100 mm flatness on anything rated IP65 or above
- Machined: cable gland, connector and display window holes, to ±0.05 mm so the gland's own seal works as designed
- Machined: threaded holes for lid fasteners, earth bonding studs and PCB standoffs, plus any window or lens seat
- Finishing: shot blast, mask the gasket land and bonding face, then powder coat to your RAL or Pantone reference
- Assembly: gasket fitting, insert installation, earth bonding continuity check and IP ingress test before packing
Design considerations for sealed aluminum enclosures
Gasket groove geometry
Make the groove 1.5 to 3 mm wide with 2 to 3° of draft on both flanks and a radius at the bottom, sized for 20 to 30% compression of the cord. A square-flanked groove will not release from the die, and a groove sized for zero compression will not seal.
Fastener spacing
Space lid screws 40 to 70 mm apart and closer at corners. Wider spacing lets the lid bow between fasteners, the gasket relaxes at mid-span, and the enclosure fails its water test at that exact point with every dimension still in tolerance.
Stiffen the lid
A flat lid is a spring. Add a peripheral flange or internal ribs, or take it to 3 mm, so fastener load spreads instead of dishing the centre. Ribs are cheaper than thickness and do not create the thermal mass that traps porosity.
Keep the seal path continuous
Never interrupt the gasket path with a gland hole, a hinge or a fastener. Every feature crossing the seal line is a leak path. Route cable entries through a wall inside the seal, not through the joint itself.
Cable gland bosses
Cast the boss with a cored pilot hole and machine the final diameter. Give the gland a flat machined seating face for its washer, and leave boss depth for the locking nut plus the wall behind it.
EMI shielding and bonding
Aluminum shields by itself, but powder coat across a joint is an insulator. Specify a masked, unpainted contact land and a dedicated earth bonding boss with a machined face wherever shielding continuity has to cross the lid joint.
Build in the thermal path
Cast a raised internal pad under each dissipating component so it can be machined flat for its thermal interface material, and put cast fins on the outside of the same wall. That turns the enclosure into the heat sink and removes an assembly.
Plan for condensation, not just ingress
Outdoor enclosures fail more often from internal condensation than from water getting past the gasket. Cast a boss for a breather vent, and shape external surfaces so water runs off rather than pooling on a horizontal lid.
Protect cosmetic surfaces
Put the parting line, gate and ejector marks on faces the end user never sees, and keep visible surfaces free of the abrupt wall thickness transitions that cause sink marks under paint.
Industries that buy die cast aluminum enclosures
Industrial automation and controls
Drive enclosures, controller boxes and field junction boxes, usually IP65 with DIN rail features cast into the base and a powder coated finish matched to the customer's machine colour.
Telecoms and networking
Outdoor remote radio, small cell and gateway housings in A360, combining a sealed cavity with external cast fins so one part is enclosure, heat sink and mounting bracket.
Instrumentation and test
Measurement and data acquisition enclosures where EMI shielding is a specification rather than a preference, and the shielding is delivered by the casting instead of a conductive coating.
Infrastructure and outdoor equipment
EV charger, street lighting control, traffic and rail-side enclosures, tested to IP66 or IP67 with a breather vent, stainless hardware and a salt spray tested coating system.
Medical devices
Equipment enclosures and instrument housings with documented lot traceability, first article inspection packages and smooth, cleanable finishes that tolerate repeated disinfection.
Consumer electronics
Thin-wall chassis, frames and set-top housings where cosmetic Class A surfaces, colour consistency across lots and shielding all have to hold at high volume.
Keep exploring
Related capabilities and resources
Manufacturing services
Aluminum alloys
Part types
Industries served
Further reading
Frequently asked questions
What IP rating can a die cast aluminum enclosure achieve?
IP65 and IP67 are routine, and IP68 is possible case by case. IP65 and above requires the mating land to be machined rather than left as-cast, because as-cast flatness of 0.1 mm per 100 mm becomes too much gap across a large lid. The rating also depends on the gasket, the glands and the fastener spacing, so we test the assembled enclosure to the rating on your drawing rather than certifying the casting alone.
Do I have to machine the sealing face, or can it stay as-cast?
Up to IP54 an as-cast land with a foam gasket generally works. From IP65 upward the land should be machined to 0.05 mm per 100 mm, and the larger the lid the more that matters, because as-cast flatness error accumulates along the perimeter. Machining the land is a single milling pass on a fixture that already exists for the gland holes, so it adds little cost relative to the risk it removes.
Does a die cast aluminum enclosure provide EMI shielding?
Yes, inherently. Aluminum is conductive, so the wall itself attenuates electromagnetic interference without the conductive paint, foil liner or vacuum-plated coating that a plastic enclosure requires to pass emissions testing. The weak point is the lid joint: a powder coated land is an insulator, so specify a masked unpainted contact land and an earth bonding boss with a machined face if shielding has to be continuous across the joint.
Should I choose a die cast aluminum enclosure or moulded plastic?
Choose aluminum when you need EMI shielding, a heat path out of the box, mechanical robustness, fire performance or a metal appearance. Choose plastic when the enclosure is electrically insulating by design, the part is very high volume and cost dominated, or the wall has to be radio transparent for an internal antenna. Tooling cost is broadly comparable at similar complexity, so the decision is nearly always functional rather than financial.
Can the gasket groove be cast instead of machined?
Yes, and it should be. A cast groove costs nothing per part once it is in the die, while a machined groove adds a contouring pass to every unit. The requirements are 1.5 to 3 mm width, 2 to 3° of draft on both flanks and a radius at the bottom so the groove releases from the die. Only the flat land either side of the groove needs machining.
What is the difference between an enclosure and a housing on this site?
An enclosure is a sealed box that protects and shields electronics, so it is engineered around gasket grooves, IP ratings, EMI shielding, cable gland bosses and lid flatness. A housing is a structural casting that carries load and locates rotating parts, so it is engineered around bearing bore concentricity, sealing face flatness, pressure tightness and load paths. If your part holds a circuit board, you are on the right page; if it holds a bearing, read the housings page.
How much does aluminum die casting tooling cost?
A single-cavity production die for a small to medium part typically runs 3,000 to 12,000 USD. Larger parts, multi-cavity dies and tools with multiple slides range from 12,000 to 25,000 USD or more. Tooling is quoted as a one-time charge, remains dedicated to your part, and is stored and maintained at our facility for the life of the program.
Request for quote
Get your enclosure quoted to an IP rating
Send your 2D drawing and 3D model with the target IP rating, gasket type and colour reference. You will get piece pricing, tooling cost and a written DFM report covering groove geometry, fastener spacing and which lands we would machine.
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