ABS and polycarbonate both get grouped under “tougher than PLA or PETG,” and buying guides sometimes present PC as simply a stronger, more expensive version of ABS. That framing undersells what actually separates them. ABS is a genuinely useful step up from PLA on its own, heat resistant enough and impact resistant enough for most functional parts. PC exists for the narrower case where a part needs real heat resistance and real impact resistance at the same time, a combination ABS cannot cover once temperatures climb. Reaching for PC without that specific requirement usually means paying a much harder print process for strength the part never actually needed.
Heat resistance is where these two genuinely diverge
Glass transition temperature, the point where a plastic starts to soften, is the clearest way to see the gap. ABS sits around 100 to 105°C, already well above PLA and enough for most enclosures and brackets kept away from direct heat. PC’s glass transition runs closer to 147°C, a jump large enough to matter for parts near a heat source or a warm enclosure, the kind of job that leaves an ABS part visibly softening. That difference is the entire reason PC exists as a hobbyist filament in the first place: it keeps its shape and strength at temperatures that would leave an ABS part soft and unreliable.
Strength and impact resistance favor PC, but ABS isn’t fragile
On tensile strength, consumer-grade ABS commonly lands in the 30 to 36 MPa range, with some formulations and additive packages pushing closer to 37 MPa on manufacturer data sheets. PC typically tests higher, with printed-part figures commonly cited in the 40 to 50 MPa class, and pure polycarbonate’s industrial reputation for impact resistance, the same toughness behind safety glasses and machine guards, carries over partially to printed parts. A well-printed PC part can survive a drop that would crack an ABS part outright. That said, ABS is not a fragile material on its own; it remains tougher and more impact resistant than PLA or PETG, and for parts that only need to survive normal handling and occasional knocks rather than a hard, sudden impact, ABS’s strength is usually enough without PC’s added cost and difficulty.
Printing setup: a wider gap than the strength numbers suggest
ABS prints in a demanding but manageable window, typically 230 to 260°C at the nozzle with a bed around 90 to 110°C, and it benefits from an enclosure or at least a draft shield to control warping, covered in FirstLayerGuide’s own ABS print settings guide. PC asks for considerably more. Nozzle temperatures commonly run 260 to 310°C, with pure PC pushing toward the top of that range and PC-ABS blends printing cooler, closer to 250 to 280°C, and bed temperatures climb to 90 to 120°C. At those temperatures a standard PTFE-lined hotend is not optional equipment to skip, it will degrade, so an all-metal hotend rated for 300°C or higher is required rather than recommended. PC also wants a genuinely sealed, heated enclosure, with a chamber temperature around 60°C often cited for tall or complex parts, where ABS can often get by with a simpler draft shield on smaller prints. FirstLayerGuide’s polycarbonate filament guide covers the full setup. On top of that, PC is hygroscopic enough that even a freshly opened spool benefits from drying, typically 70 to 90°C for 6 to 12 hours, a step ABS rarely needs to the same degree.
Cost and when the jump is actually worth it
ABS remains one of the cheaper engineering-adjacent filaments, commonly $20 to $35 per kg depending on brand. PC costs meaningfully more; filament pricing trackers that cover the wider engineering tier put polycarbonate and carbon-fiber-reinforced nylon at roughly three to five times ABS’s price, though PC-specific pricing is tracked less consistently than more common materials, so treat that multiplier as a rough estimate rather than a fixed number. Between the price gap, the all-metal hotend requirement, and the near-mandatory heated enclosure, switching to PC is a real investment in equipment as much as in filament. It pays off specifically when a part has to hold its shape and resist impact at an elevated temperature at the same time, jigs near heat sources, brackets that see both load and warmth, or enclosures for electronics that run hot. If a part only needs one of those two properties, ABS usually covers moderate heat well enough, and FirstLayerGuide’s engineering filaments overview and ABS vs ASA comparison cover the cheaper alternatives worth ruling out first. Reach for PC once ABS has already been tried and has already failed on heat or impact grounds, not as a default upgrade.