A PTFE-lined hotend runs a PTFE tube close to or into the nozzle, so filament slides on a smooth, low-friction liner. An all-metal hotend removes that liner and relies on a stainless steel or titanium heatbreak to manage the transition from hot to cool. The swap is about maximum safe temperature, not which one prints PLA better.
What the liner is doing
PTFE has a genuinely low coefficient of friction, which is why Bowden setups in particular use it: filament needs to slide a long distance with minimal drag. The tradeoff is that PTFE starts to degrade above roughly 250°C, releasing fumes and losing its grip on the tube wall over time. That ceiling is fine for PLA, PETG and most TPU, but it rules out anything that needs a genuinely hot nozzle.
What all-metal removes
Without a liner, the heatbreak itself has to manage the thermal transition cleanly, which means tighter machining tolerances inside the bore. Get that internal step wrong and you get heat creep: the heat zone spreads further up the heatbreak than intended, filament softens too early, and the printer clogs even though the nozzle temperature looks correct on the display. A properly designed all-metal hotend with adequate heatsink cooling avoids this, but it is less forgiving of a weak cooling fan than a PTFE-lined design.
The real reason to choose one
All-metal hotends can reach 300°C or higher, which opens the door to nylon, polycarbonate and some carbon-fiber-filled blends that PTFE-lined hotends cannot run safely. If your filament list stays inside PLA, PETG and TPU, a PTFE-lined hotend has no real downside and can be slightly more tolerant of retraction settings. If you already know you want to print polycarbonate or nylon, all-metal is not optional.
What ships by default now
Most current consumer printers, including Bambu Lab, Prusa’s Nextruder and Creality’s K-series, ship all-metal hotends out of the box, because an all-metal design can print everything a PTFE-lined one can plus the high-temperature materials, provided the firmware profile and cooling are set up correctly. The practical decision today usually comes up when upgrading an older machine that still has a PTFE-lined stock hotend, not when buying new.
Hotend checklist
- Confirm your printer’s actual PTFE-lined temperature ceiling before assuming a small overshoot is safe.
- Match the nozzle material to the filament as a separate decision from the hotend liner.
- If moving to all-metal, verify the heatsink fan and cooling shroud are adequate for the higher temperatures.
- Reslice with a profile built for the new hotend rather than reusing old retraction and temperature settings.