Material guide
High-Temperature Plastics: Max Service Temperature Chart
How hot can each plastic run? A chart of typical maximum continuous service temperatures for common and high-performance plastics, from polyethylene to PEEK, Torlon and Vespel, plus how to pick for heat.
Rough continuous limits: polyethylenes, PVC and acrylic top out around 140–190°F; acetal and nylon around 180–210°F; polycarbonate around 250°F; PVDF around 300°F; Ultem around 340°F; PPS around 425°F; PEEK, PTFE and Torlon around 480–500°F; and Vespel polyimide around 550°F.
Temperature chart
| Plastic | Typical max continuous | Notes |
|---|---|---|
| PVC | ~140°F (60°C) | Softens early; CPVC goes higher |
| Acrylic | ~160–190°F (70–88°C) | Clear; not for hot parts |
| HDPE / UHMW | ~180°F (82°C) | High thermal expansion |
| ABS | ~160–180°F (70–82°C) | General-purpose |
| Acetal | ~180°F (82°C) | Short-term higher |
| Polypropylene | ~180–210°F (82–99°C) | Handles hot water better than PE |
| CPVC | ~200°F (93°C) | Hot chemical piping and duct |
| Nylon 6/6 | ~200–210°F (93–99°C) | Heat-stabilized grades go higher |
| PET | ~210°F (99°C) | Low moisture, stable |
| Noryl (PPO) | ~220°F (104°C) | Good in hot water |
| Polycarbonate | ~250°F (121°C) | Clear and tough |
| PVDF | ~280–300°F (138–149°C) | Chemical processing |
| PSU / PPSU | ~300–340°F (149–171°C) | Steam-sterilizable, medical |
| Ultem (PEI) | ~340°F (171°C) | Flame resistant, strong |
| PPS | ~425°F (218°C) | Very chemically resistant |
| PEEK | ~480°F (249°C) | Steam and chemical resistant |
| PTFE | ~500°F (260°C) | Soft; creeps under load |
| Torlon (PAI) | ~500°F (260°C) | Strongest at temperature |
| Vespel (PI) | ~550°F (288°C) | Doesn't melt |
Typical long-term limits for unfilled grades in air with light load. Limits under load, in steam or with chemicals are lower.
How to choose for heat
- Start with the real number. What temperature does the part actually see, for how long, and under what load? A part that sees 300°F for a few seconds is very different from one that sits at 300°F all day.
- Load lowers the limit. Plastics creep and soften faster under load. If the part is structural and hot, look at heat deflection temperature and creep data, and consider glass- or carbon-filled grades.
- Environment matters. Hot water and steam degrade nylon, acetal, polycarbonate, Torlon and polyimide over time. PEEK, PPS, PSU/PPSU and PVDF handle them much better.
- Don't overspecify. Each step up the temperature ladder costs a lot more. Choose the lowest-cost material that clears your real temperature with a margin.
Common high-temperature picks
Up to ~250°F
- Polycarbonate (clear parts)
- Heat-stabilized nylon
- Noryl, PET, CPVC
~250–350°F
- PVDF (chemical service)
- PSU / PPSU (steam, medical)
- Ultem (strength, flame resistance)
Above ~350°F
- PPS, PEEK (chemicals, steam)
- PTFE (low friction, seals)
- Torlon, Vespel (strength, wear)
Tip from the counter: "high temp" on a request can mean anything from a warm dishwasher to an oven door. Get the number and the duty cycle first; it's often the difference between a $20 part and a $200 one.
Comparing the top-end options? See PEEK vs Ultem and Torlon vs PEEK vs Vespel.
Common questions
What plastic can withstand the highest temperature?
Among commonly machined plastics, polyimides like Vespel handle the highest continuous temperatures, around 550°F (288°C), and don't melt. Torlon (PAI), PTFE and PEEK follow at roughly 480 to 500°F. For short exposures, several of these can go higher still.
How hot is too hot for plastic?
It depends entirely on the plastic. Commodity plastics like PVC, polyethylene and acrylic start softening between about 140°F and 190°F. Engineering plastics like acetal and nylon handle about 180 to 210°F. High-performance plastics like PEEK, PTFE and Torlon handle roughly 480 to 500°F.
Will plastic melt at 140 degrees?
Most rigid plastics won't melt at 140°F, but some soften and lose strength near there. PVC is typically limited to about 140°F, and polyethylene and acrylic to around 160 to 180°F. Engineering and high-performance plastics are fine well above that.
What's the difference between continuous use temperature and heat deflection temperature?
Continuous use (or service) temperature is roughly how hot a plastic can run long-term without unacceptable degradation. Heat deflection temperature (HDT) is a short-term lab test of the temperature where a loaded bar bends a set amount. HDT is useful for comparing stiffness when hot; continuous use temperature is better for long-term heat exposure.
Does glass fill raise a plastic's temperature rating?
Glass or carbon fill raises stiffness at temperature and heat deflection temperature, sometimes dramatically, so filled grades hold their shape better when hot. It doesn't usually raise the long-term continuous use temperature much, because that's limited by how the polymer itself ages.
Temperatures in this chart are typical maximum continuous service temperatures for common unfilled grades, in air, with little or no load. They're for rough comparison only. Real limits depend on load, time, environment (steam, chemicals, oxygen), grade and fillers, and manufacturers rate their materials differently. Check the manufacturer's datasheet and the material certifications for your exact grade, and confirm with your supplier before you specify.
Who stocks and machines it
Distributors that stock these materials and shops that machine or fabricate them, from the Stock & Shape directory.
PEEK
- Interstate Advanced Materials – Portland Portland, OR
- Piedmont Plastics – Knoxville Knoxville, TN
- Port Plastics – Albuquerque Albuquerque, NM
- Total Plastics – Chicago Elk Grove Village, IL
- AIP Precision Machining Daytona Beach, FL
- Avion USA Sanborn, NY
- Carlson Tool & Manufacturing Cedarburg, WI
- No Limit Swiss Mentor, OH
Ultem (PEI)
- Piedmont Plastics – Pittsburgh Cranberry Township, PA
- Port Plastics – Seattle Seattle, WA
- Pro Plastics Linden, NJ
- Professional Plastics – Portland Tualatin, OR
- Faro Industries Rochester, NY
- Machine Specialty & Manufacturing Youngsville, LA
- Remarc Manufacturing Reno, NV
- Sure-Fab Two Harbors, MN
PTFE (Teflon)
- Calsak Plastics – Portland Portland, OR
- Curbell Plastics – Dallas-Fort Worth Arlington, TX
- Piedmont Plastics – Salt Lake City Sandy, UT
- Total Plastics – Tampa Tampa, FL
- Carlson Tool & Manufacturing Cedarburg, WI
- H. H. Arnold Co. Rockland, MA
- MF Engineering Company Bristol, RI
- NN, Inc. – Algonquin Algonquin, IL
PPS
- AIP Precision Machining Daytona Beach, FL
- Boyd Machine Co. Souderton, PA
- Evolution Manufacturing Hubbard, OR
- RPM Engineering Virginia Beach, VA
Torlon (PAI)
- Port Plastics – Phoenix Phoenix, AZ
- Professional Plastics – Portland Tualatin, OR
- AIP Precision Machining Daytona Beach, FL
- Boyd Machine Co. Souderton, PA
- Evolution Manufacturing Hubbard, OR
- Portland Precision Manufacturing Portland, OR
Vespel (PI)
- Curbell Plastics – Seattle Fife, WA
- Professional Plastics – Portland Tualatin, OR
- AIP Precision Machining Daytona Beach, FL
- Allied Precision Middletown, DE
- Dover High Performance Plastics Dover, OH
- HD Machining Solutions Elizabethton, TN