Which material for a part that gets hot

The right question is not «how many degrees can it take»

The figure that matters is called heat deflection temperature under load, and it depends on two things: the material, but also the stress on the part at that moment. An unstressed part takes more than one bolted down under tension, because under load the plastic creeps rather than simply softening.

The second question matters just as much: for how long? A part that sees 80 °C for ten seconds has nothing in common with one that lives at 60 °C all day. Plastic has no short memory: repeated cycles eventually deform it even below the theoretical limit.

When you describe a need to us, those two pieces of information are worth more than a material name: tell us where the part lives and what it puts up with.

The real limits, material by material

PLA — up to about 55 °C. That is low, and it is the commonest trap. A PLA part left in a car in the sun warps: the cabin passes 60 °C as soon as it is 25 °C outside. PLA stays excellent for anything living indoors at room temperature, and it gives the best detail.

PETG — up to about 70 °C. The good compromise for daily use. It takes hot tap water, kitchen steam, a dish out of the oven set down for two minutes. It does not go in the dishwasher, though: a 70 °C cycle repeated several times eventually warps it.

ABS — up to about 90 °C. The first real technical step. It needs a heated chamber and drying at 80 °C before printing, failing which it bubbles and lifts. It is also the material for thermoforming tools, which hold 105 °C after annealing.

ASA — like ABS, plus UV. Same thermal limits, but it neither yellows nor turns brittle in sunlight. For anything living outdoors it is the default choice, and there is not much to debate.

PC — beyond 110 °C. Polycarbonate absorbs both temperature and impact. It costs more, it is trickier to print, and it is only worth it when the 90 °C of ABS is no longer enough.

PA6-CF — up to 120 °C continuous. Carbon-filled nylon adds high stiffness and very low creep. It is the material for parts under permanent load in a warm environment.

PPS-CF — up to 200 °C. Reserved for extremes: powder-coating masks, zones near an oven. On request, and rarely necessary.

Three situations that catch everyone out

The electronics enclosure. A component running at 50 °C heats the air around it, and the air in a closed box climbs well above the temperature of the component itself. A PLA enclosure around a power supply is an enclosure that warps in summer.

The part behind glass. Behind a windscreen or a south-facing shop window, the greenhouse effect drives the surface of a black object far above air temperature. A black PLA object in a south-facing display does not survive the summer.

The dishwasher. None of our materials survives it in repeated cycles. It is not a question of paying for a better material: it is the combination of heat, moisture and detergent. Sponge washing, without exception.

In practice

If your part lives indoors with no particular stress: PLA. If it is used daily, handled, exposed to water: PETG. If it lives outdoors: ASA. If it genuinely gets hot: ABS, then PC, then PA6-CF.

When in doubt, just tell us where the part will be fitted and what it will do. We choose it with you — and the cheapest material is often the right one.

Also worth reading

• Polycarbonate (PC) parts – high temperature and impact resistance
• UV-stable ASA parts for outdoor applications
• High-temperature masking caps and plugs for powder coating