PC and PC/ABS dominate housings for electronics, appliances, and automotive interiors, and they get confused more than any other pair of grades. Both are amorphous, both paint and plate well, and both can hit V-0 flame ratings. The differences hide in heat resistance, chemical resistance, low-temperature toughness, and flow.
Quick comparison
| Property | PC (unfilled) | PC/ABS (typical) |
|---|---|---|
| HDT @ 1.8 MPa | 125–135°C | 95–110°C |
| Notched impact (23°C) | Very high (no break) | High (35–60 kJ/m²) |
| Notched impact (−30°C) | Still ductile | Becomes brittle sooner |
| Melt flow (MFR) | Low–medium | Higher — flows better |
| Chemical resistance | Poor vs many agents | Moderate — better stress-crack behavior |
| Continuous use (RTI) | 110–120°C | 80–95°C |
| Relative cost | Higher | Lower |
Choose PC when...
- The part sees sustained heat above ~100°C: lamp housings, components near motors or heaters, under-hood-adjacent trim.
- The part must survive impact at low temperature (freezer hardware, outdoor enclosures, safety components).
- Transparency or optical clarity is required — PC/ABS is always opaque.
- Creep resistance under long-term load matters: PC's higher Tg holds dimension better under sustained stress at elevated temperature.
Choose PC/ABS when...
- The part is a cosmetic housing at moderate temperature: consumer electronics, IT equipment, appliance covers, automotive interior trim.
- Thin walls or long flow paths demand better moldability — PC/ABS fills easier and at lower melt temperature than PC.
- The part contacts cleaners, alcohols, or cosmetic fluids: PC is notoriously prone to environmental stress cracking; the ABS phase improves resistance.
- Cost matters: PC/ABS typically saves 10–25% on material cost versus PC at equivalent stiffness.
- Painting and texture replication are priorities — PC/ABS takes paint and mold texture slightly better than PC.
Decision framework
Work through four questions in order. First: what is the maximum continuous temperature, including self-heating from electronics? Above 100°C continuous, PC wins outright. Second: does the part see chemical exposure (cleaning agents, hand sanitizers, plasticizers from cables)? If yes, lean PC/ABS or a chemical-resistant PC grade. Third: what is the lowest service temperature combined with impact risk? Below −20°C with drop risk, PC is the safer choice. Fourth: wall thickness and flow length — thin, complex housings often simply cannot fill with standard PC grades.
When the answers conflict (e.g. high heat plus thin walls), ask about high-flow PC or high-heat PC/ABS blends — specialty grades exist precisely to close these gaps, and our catalog carries both.
Common mistakes
- Specifying PC for a warm cosmetic housing purely on toughness — you pay for impact you don't need and fight sink marks.
- Specifying PC/ABS near a heat source because the part 'used to be ABS' — check the new thermal budget, not the old BOM.
- Ignoring stress cracking: a PC enclosure wiped with isopropyl alcohol can crack within weeks under screw-boss stress.
Need help picking a grade?
Ask ResinIQ — our AI material advisor — or browse the full catalog of engineering resins.