Small-Run PCB Enclosures: 3D Printing or Sheet Metal?

Small-run PCB enclosures sit in an awkward spot: too few units to justify molding, too many to treat as one-off prototypes.

Is 3D Printing the Best Way to Make a Small Run of 100 PCB Enclosures, or Is Sheet Metal Better?

Neither process wins outright. Printed nylon suits complex housings with bosses, snap fits, and curves, while sheet metal suits simple box-like enclosures, so at about 100 units, quote the same design both ways.

An r/3Dprinting poster asked whether 3D printing was the best approach for a small production run of about 100 enclosures for a PCB. At that quantity, injection molding tooling is hard to justify, so the realistic options are industrial powder-bed printing (SLS/MJF), formed sheet metal, or machining.

When printed nylon wins

• Complex shapes. Integrated bosses, snap fits, cable channels, curved housings, and internal ribs don't need tooling or extra setups.
• Changing designs. There's no tooling and no flat pattern to redo, so a revision is just a new file.
• Light weight and electrical insulation, which suit handheld or low-voltage devices.
• Mounting PCBs. Bosses can take heat-set inserts or be tapped directly (see Heat-Set Insert Hole Size for SLS and MJF Nylon and Why Does a Tapped Hole in a 3D Printed Nylon Part Strip Sooner Than the Same Thread in Machined Delrin?).

Downsides: as-printed MJF is usually grey with a slightly grainy surface unless it's dyed or finished, and plastic doesn't block EMI the way metal does.

When sheet metal wins for small-run PCB enclosures

• Simple box-like shapes: flat panels, bends, cutouts, and vents
• Shielding, grounding, or heat spreading, where a metal enclosure helps
• Stiffness and durability in thin walls
• Hardware. PEM studs, nuts, and standoffs give strong, reusable threads for PCB mounting.

A two-piece design (a U-shaped base and a U-shaped cover, or a box and a lid) keeps every corner a simple bend.

What about cost?

Online guides publish break-even quantities, but they vary widely with part size, material, and finish. Don't trust a rule of thumb. Quote the same design both ways.

Related: why more bends raise sheet metal cost. Source: Forge Labs MJF design guide.

At DigiForge

We offer both routes: printing in MJF Nylon, SLS Nylon PA12, MJF Glass-Filled Nylon, SLS PP GB Glass Filled, and TPU (±0.3 mm or ±0.3%, whichever is greater), and sheet metal with laser cutting, press-brake forming, and PEM insertion in Cold Rolled Steel, Galvanized Steel, Aluminum 5052 and 6061, and Stainless 304 and 316 (±0.13 mm cut, ±0.5° bend). Upload a STEP file for each version and compare the instant quotes.