PTFE Tube Calculator — Replacement Interval

PTFE (Teflon) has a maximum continuous service temperature of about 260°C and a melting point of 327°C, but in a 3D-printer hot end the tube tip is recommended to stay below roughly 240°C. Sustained printing above that gradually chars and degrades the PTFE, and above ~260°C it off-gasses toxic fumes (such as PFIB and phosgene). Even at lower temperatures PTFE slowly hardens and loses its low-friction properties over many print hours, leading to increased extrusion resistance and clogs.

Capricorn is a premium PTFE tube brand with tighter inner diameter tolerances (1.9mm vs 2.0mm standard) and better thermal resistance. The tighter bore reduces filament play, improving retraction performance and reducing stringing.

Switch to all-metal if you regularly print above 240C (PETG+, ABS, ASA, Nylon, PC). All-metal hot ends have no PTFE in the heat zone, eliminating degradation concerns and allowing temperatures up to 300C+.

Signs include: increased clogs, especially during retraction; discolouration of the tube end near the hot end (white turning yellow/brown); inconsistent extrusion; and grinding sounds from the extruder. Inspect the hot end end of the tube periodically.