Here’s a question I get a lot: why do the same two thermoplastics show up inside nearly every consumer electronic device on the market? Pull apart any router, power tool handle, TV remote, phone charger case, or medical handheld scanner — odds are the enclosure is either ABS or PC/ABS. I’d put the number at 80%+, conservatively. That’s not coincidence. That’s material science driven by a simple economic force: these two resins deliver the best combination of surface quality, impact performance, and moldability at a price point that keeps BOMs under control. Here’s the math on why.
The ABS Case
ABS is the workhorse of consumer electronics enclosures because it does one thing better than almost any engineering thermoplastic: it makes a beautiful surface finish right out of the mold. You can texture it, paint it, pad-print it, or laser-mark it without any secondary preparation. That matters when your product lives on a retail shelf or a customer’s desk.
The numbers back it up. ABS flows into wall thicknesses as low as 0.8 mm in a standard injection mold, which means you’re using less material per part and cycling faster. Raw material runs around $1.80-2.50/kg — roughly half what you’d pay for polycarbonate. For a 200-gram enclosure at 500,000 units per year, the material cost difference alone is $50,000-80,000 annually.
Heat deflection temperature at 0.45 MPa sits at 90-105°C, which is sufficient for most consumer electronics that don’t generate serious internal heat. Think wall warts, set-top boxes, children’s toys, vacuum cleaner housings. It’s enough.
But ABS has limits. Continuous use above 70-80°C causes creep and warpage. UV exposure turns it brittle and chalky within months if uncoated. Notched Izod impact runs 150-350 J/m — adequate for tabletop devices, but not something I’d spec for a tool that needs to survive a 1.5-meter drop onto concrete.
Here’s my take: ABS is the default choice until the application gives you a reason not to use it. Save the money, take the surface finish, and move on.
The PC/ABS Case
When your enclosure needs to survive drops, PC/ABS is the upgrade path. The polycarbonate fraction delivers 400-700 J/m notched Izod — two to three times what straight ABS can manage. That’s the difference between “customer returns a scratched unit” and “customer returns a shattered one.” At 50,000 units with a 2% field failure rate and $15 per RMA, the savings from a drop in returns covers the material premium in about three months.
HDT climbs to 110-125°C at 0.45 MPa. That opens up enclosures for power tools, laptop chargers, and set-top boxes that sit near heat sinks. UV stability is moderate — better than ABS, but still not outdoor-grade without a paint system.
Cost runs $2.80-4.00/kg, about 1.8x ABS. The material is less forgiving at very thin walls — you’re typically looking at 0.8-1.0 mm minimum — and the surface finish, while good, doesn’t match ABS for paint adhesion and texture clarity. You pay for the toughness.
I’ve spec’d PC/ABS on more projects than I can count where the engineering team initially wanted ABS for cost reasons. One drop-test cycle later, the conversation changes. Here’s the rule I use: if the device is handheld and valued over $50 retail, start with PC/ABS. If it sits on a desk and doesn’t move, ABS is fine. That rule has never let me down.
Comparison Table
| Property | ABS | PC/ABS | PC | PP |
|---|---|---|---|---|
| Surface Finish | Excellent | Good | Fair | Poor |
| Paint/Texture | Excellent | Good | Fair | Poor |
| HDT @ 0.45 MPa | 90-105°C | 110-125°C | 130-140°C | 90-110°C |
| Notched Izod | 150-350 | 400-700 | 600-900 | 50-200 |
| UV Resistance | Poor | Moderate | Moderate | Poor |
| Cost Index | 1.0x | 1.8x | 1.5x | 0.7x |
When You Need Something Else
The ABS/PC-ABS duopoly covers most ground, but three edge cases demand something different.
PC alone — when you need optical clarity or HDT above 130°C. Light pipes, display windows, and high-heat enclosures (130-140°C HDT). Surface finish is fair at best, and the flow is worse — you’ll need thicker walls and longer cycles.
Nylon (PA) — for structural components that take threaded inserts or bear load. Think hinge bosses, battery tray frames, and internal chassis brackets. Nylon absorbs moisture, which changes dimensions and mechanicals — not great for cosmetic enclosures, but unmatched for strength in thin sections.
PP — the lowest-cost option at roughly $1.20-1.80/kg, with excellent chemical resistance and fatigue life (integral living hinges). Surface finish is poor, paint adhesion is worse, and it feels cheap in the hand. Best kept for hidden internal parts and low-cost appliances.
PBT/PC — when chemical resistance and impact need to coexist. Solvent resistance for devices that see cleaning agents, combined with decent impact for handheld use. Higher cost than PC/ABS and harder to process.
Decision Guide
| Application | Go-To | Why |
|---|---|---|
| Desk-bound enclosure | ABS | Best surface, lowest cost, good enough impact |
| Handheld consumer device | PC/ABS | Drop survival, moderate heat, good finish |
| Power tool housing | PC/ABS | Impact + heat, paint adhesion optional |
| Transparent window/light pipe | PC | Optical clarity, high HDT required |
| Structural bracket/hinge | Nylon | Threaded insert retention, load bearing |
| Disposable/low-cost appliance | PP | Lowest cost, chemical resistant |
The math on material selection for enclosures isn’t complicated. ABS until you hit an impact, heat, or UV limit. PC/ABS when those limits bite. Something niche only when neither works. Most projects fall into the first two buckets, and that’s why these two materials own the category.
Need help deciding between ABS and PC/ABS for your next enclosure? Our engineering team works with both daily and can walk through the trade-offs with your numbers.