Choose a material for high-temperature parts

Heat is the most common reason a good-looking print fails in service. A bracket near a motor, a clip inside a parked car or a fixture next to an oven can all sag, creep or warp long before they ever reach their “rated” temperature. This guide explains what actually goes wrong and how to choose a material that will hold its shape.

What fails in hot applications

Plastics do not melt all at once. As they warm up, they get softer, and under a load they start to bend slowly. That is the real failure: a part that slowly droops, loses clamp force or drifts out of tolerance. Three things make it worse.

• Load. A part carrying weight or a screw preload softens at a lower temperature than one sitting free.
• Time. Creep builds over hours and days. A short test at temperature can look fine and still fail in a week.
• Thin sections. Thin walls heat through quickly and have little stiffness to spare.

Which properties matter

Start with heat deflection temperature (HDT). It tells you the temperature at which a standard bar bends a set amount under a set load. It is the most useful single number for loaded parts.

Then look at glass transition temperature (Tg), where an amorphous plastic turns from rigid to rubbery, and Vicat softening temperature. For semi-crystalline materials such as nylon, PP or PEEK, the melting temperature sets the absolute ceiling, but useful stiffness ends well below it.

Across the materials we flag as high-temperature, HDT spans 100–305 °C (median 147.5 °C, 128 bahan).

1. PLA 3148–137
2. PETG 1558–78
3. ABS 1770–118.1
4. ASA 887–100
5. PC 1299–163
6. PA6 1390–200
7. PEI 13152–215.12
8. PEEK 11140–305

Bar = terendah hingga tertinggi, titik = median. 120 bahan, terus daripada pangkalan data kami.

Material families that usually work

• ABS and ASA handle a warm room or a car interior better than PLA or PETG, and print easily with an enclosure.
• PC and PC blends step up again, with good toughness.
• Nylons, especially fibre-filled ones, keep stiffness well when hot because the fibres carry load as the polymer softens.
• PEI, PEKK, PEEK, PPS and PPSU are the high-performance group for continuous high heat. They need a high-temperature printer with a heated chamber.
• High-temperature resins can reach very high HDT but tend to be brittle. They suit moulds, heat-test fixtures and air-flow parts more than impact parts.

Process considerations

FFF gives you the widest choice, but layer bonding is weaker than the bulk material, so heat plus load across layers is a weak point. Resin parts are nearly isotropic, but their quoted HDT usually assumes a full thermal post-cure. Powder processes such as SLS and MJF give tough, isotropic nylon parts with moderate heat resistance. See the process guide for more.

Design and post-processing tips

• Anneal semi-crystalline filaments such as PLA, PA and PEEK when the datasheet recommends it. Crystallinity raises heat resistance, but parts can shrink or warp, so test and allow for it.
• Thermally post-cure resins exactly as the manufacturer specifies. Skipping it can leave you far below the datasheet HDT.
• Add ribs and thicker walls rather than relying on the material alone. Stiffness from geometry does not fade with temperature.
• Use metal inserts for screws in hot zones. Threads cut into plastic creep and loosen.

A shortlist from our data

The highest HDT filaments in our catalog:

And the highest HDT resins:

We also list 6 high-temperature powders. Check the test load on every value before you compare them.

Common mistakes

• Choosing by melting point instead of HDT.
• Comparing a 0.45 MPa HDT with a 1.8 MPa HDT.
• Ignoring time. Test under real load for days, not minutes.
• Forgetting the printer. PEEK on an open-frame printer will not give datasheet results.
• Skipping annealing or post-cure, then blaming the material.

See all high-temperature materials 128 bahan