Part Type
CNC Machined Aluminum Enclosures & Housings
A case built around your board, not the other way around.
A CNC machined aluminum enclosure is a case cut from solid billet, usually a two-piece base and lid, with internal bosses, milled pockets, and bored connector holes sized to your board instead of poured into a die-cast mold. Cutting from billet skips casting tooling entirely, so it wins at quantities of 1 through a few hundred, holds tighter tolerances on cutouts and mating faces, and lets you revise the design with a new toolpath rather than a new mold. Send a STEP file and a PDF through the quote form and a real person sends back price, material, and lead time in 24-48 hours, with no minimum order.
Updated June 2026
What a machined enclosure actually is
Most machined enclosures are a two-piece job: a base that holds the electronics and a lid that closes over it. The base gets milled pockets to clear the board, internal bosses tapped or counterbored for standoffs, bored holes for connectors and cable glands, and a flat sealing face around the rim. The lid carries its own pockets for display windows, buttons, and vents, plus the matching bolt pattern. Because every feature is cut from solid aluminum, walls, ribs, and mounting points can land exactly where the board needs them.
That is the difference from a plastic project box you drill out by hand. The connector openings, the standoff heights, and the PCB outline all live in one CAD model, so the case fits the board on the first build instead of after three rounds of files and shims. It also means EMI and grounding bosses, heat-sink pads, and gasket grooves are part of the part, not afterthoughts.
When machined beats die-cast
Die casting is the right call when you are making tens of thousands of identical enclosures: the mold cost spreads thin and per-piece prices drop hard. That math only works at high volume. Below it, the casting tooling never pays for itself, and a machined enclosure wins on every other axis at quantities of 1 through 500.
Machining from billet means no casting tooling to amortize, so a run of ten costs ten parts, not ten parts plus a mold. Tolerances on connector cutouts and mating faces come in tight, where a casting needs draft and secondary operations to clean up. Gasket grooves for an IP-rated seal, EMI shielding bosses, and washdown-ready faces get cut directly. And when the board changes, a revision is a new toolpath, not a scrapped mold and a six-week wait. For low-volume electronics enclosures and robotics housings, that flexibility is usually worth more than the casting unit price.
Materials, sealing, and finish
6061 aluminum is the default: light, stiff, easy to cut, and happy to anodize. For a sealed enclosure rated to keep out dust and water, a machined gasket groove around the rim takes an O-ring or die-cut gasket, and a flat mating face held tight keeps the seal even. Harsh duty, marine, or washdown work moves to stainless for corrosion resistance.
Finish is where enclosures earn their look. Anodize Type II in clear or black is the standard call: corrosion and scratch resistance with a clean surface, and it keeps tight cutout dimensions. Powder coat adds durable color and a thicker film for outdoor use. Bead blast gives an even matte texture before anodize or on its own. Bare faces and threaded bosses can be masked so grounding and ground-path contact stay metal-to-metal.
What to put on the print
Connector and display cutouts are where fit lives or dies, so tolerance them tight: a USB or D-sub opening held to ±0.003 in seats the connector clean, while the outside walls can breathe at ±0.010 in. Call out gasket-groove width and depth for your O-ring cross-section, not a guessed slot, and note the target seal or IP rating so the groove and face finish match it.
Spell out standoff and PEM-style boss callouts: thread size, depth, and whether a press-in insert goes in after machining. Unlike casting, draft is not required, so vertical walls stay vertical and you keep usable internal volume. Give wall thickness a floor around 0.080 in for rigidity on aluminum, more where a connector torques on it, and a note on which face is the datum keeps the base and lid mating true.
Questions
Before you send a job.
01 When does a machined enclosure beat a die-cast one?
At low and mid volume, roughly 1 through 500 pieces, machining from billet wins because there is no casting mold to pay off first. It also holds tighter tolerances on connector cutouts and mating faces and lets you revise the design without scrapping tooling. Die casting takes over once you are making tens of thousands of identical units and the mold cost spreads thin.
02 Can a machined aluminum enclosure be sealed or IP-rated?
Yes. A gasket groove is cut around the rim to take an O-ring or die-cut gasket, and the mating face is held flat and to a fine finish so the seal stays even. Tell us the target seal or IP rating and the O-ring cross-section, and the groove width, depth, and face are sized to suit it.
03 What tolerances are realistic on connector cutouts?
Connector and display openings are typically held to ±0.003 in so the part seats clean without slop, while outer walls and non-critical features sit at ±0.005 to ±0.010 in. Tightening only the cutouts and mating faces keeps the part accurate where it matters and the price sensible everywhere else.
04 Do you need draft angles like a casting?
No. Casting needs draft so the part releases from the mold, which eats into usable internal volume. A machined enclosure has vertical walls cut straight from billet, so you keep full internal space and the standoff and boss positions stay exactly where the CAD puts them.
05 What files do you need to quote an enclosure?
A STEP file of the base and lid plus a PDF drawing calling out cutout tolerances, gasket grooves, boss threads, and finish is the ideal package. A clean dimensioned drawing alone works too. With those, a real-person quote with price and lead time comes back in 24-48 hours.
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