Quick3D Melting temperature
Melting temperature applies to semi-crystalline plastics. Learn what it tells you about printing and heat, and why many materials have none.
What it means in practice
The melting temperature (Tm) is where the ordered, crystalline regions of a plastic break down and the material becomes a melt. Only semi-crystalline plastics have one, such as PLA, nylon, PP, PEEK and TPU.
Key takeaways
- Only semi-crystalline plastics have a melting temperature; amorphous plastics and cured resins do not.
- Tm is mainly a processing number for printing, sintering and annealing.
- In service it is an absolute ceiling; parts fail long before reaching it.
- A blank Tm usually means amorphous or thermoset, not missing data.
Many materials have no melting point at all:
Amorphous plastics
Amorphous plastics (ABS, ASA, PC, PETG) soften gradually above their glass transition. There is no sharp melt.
Cured resins
Cured resins are cross-linked thermosets. They do not melt. They soften and, at high enough heat, decompose.
Where it exists, Tm is mainly a processing number:
- FFF printing: the nozzle runs well above Tm so the plastic flows.
- SLS and MJF: the powder bed is held just below Tm, and energy is added to fuse each layer. A material with a clear gap between melting and recrystallising is easier to sinter.
- Annealing: parts are heated to between Tg and Tm to grow crystals and improve heat resistance.
Watch out
For service use, Tm is an absolute ceiling. A semi-crystalline part may keep some stiffness above Tg, but it fails long before it reaches Tm.
How it’s measured
- DSC (ISO 11357-3, ASTM D3418): a small sample is heated at a steady rate. Melting shows as a peak in the heat flow. Tm is usually the top of that peak.
- Units: °C.
How to read and compare it
- A peak, not a point. Melting happens over a range. Sheets may quote the peak, the onset or a span.
- Heating rate and history. Results depend on the rate and on whether the first or second heating is reported.
- Grade differences. PLA’s Tm, for example, shifts with its exact recipe, and some grades barely crystallise.
- Blank is normal. A missing Tm usually means the material is amorphous or a thermoset, not that data is lost.
- Not a print setting. Use the manufacturer’s recommended nozzle and bed temperatures, not Tm.
Range in our catalog
- All materials with a melting point: 120–340 °C (median 178 °C, 94 materials)
- Filaments: 130–340 °C (median 178 °C, 68 materials)
- Powders (SLS and MJF): 120–204 °C (median 192 °C, 17 materials)
- High-performance materials: 170–340 °C (median 325 °C, 16 materials)
- PLA: 145–177.23 °C (median 153 °C, 22 materials)
- PLA 20145–177.23
- TPU 3144–174
- PA12 5171–178
- PA6 4198–218.5
- PPS 3279.6–283
- PEKK 4305–340
- PEEK 5338–340
Bar = lowest to highest, dot = median. 44 materials, live from our database.
Highest in our catalog
| Material | Polymer | Melting temperature |
|---|---|---|
| Kexcelled THE K11 PEEK | PEEK | ~340 °C |
| Kexcelled THE K11 PEEK CF10 | PEEK | ~340 °C |
| Kexcelled THE K11 PEEK GF10 | PEEK | ~340 °C |
| Kexcelled THE K11 PEKK | PEKK | ~340 °C |
| Kexcelled THE K12 PEEK Ultra | PEEK | ~340 °C |
Good to know
A list of the lowest values is less useful here: a low melting point mostly tells you about print settings, not quality.
Related properties
- Glass transition temperature — the lower thermal transition.
- Heat deflection temperature — the practical heat limit under load.
- Vicat softening temperature — where the surface softens.
- Density — also shifts with crystallinity.
See high-performance materials 58 materials