ProTechTrader PTFE Tubing 3 mm OD 2 mm ID 1.75 mm filament

6-inch PTFE thermal barrier for 1.75 mm filament

This ProTechTrader tube is cut to six inches and sized 3 mm outer diameter by 2 mm inner diameter. It fits MK9-style hot ends found on CTC printers and several Replicator clones. The polytetrafluoroethylene construction handles the heat break zone where filament transitions from cool to molten. Makers maintaining or upgrading Bowden extruders on compatible machines will use it as a direct replacement.

Low-friction PTFE reduces extrusion resistance

The smooth bore lets 1.75 mm filament slide with minimal drag, so the extruder motor runs cooler and retractions stay crisp. Because PTFE insulates well, the sharp temperature gradient at the heat break is preserved, limiting premature softening that causes jams. In normal printing the tube adds virtually no mass and draws no power, leaving the printer’s thermal and acoustic profile unchanged.

Replaces worn or deformed Bowden liners

Swap it when the original liner shows scoring, flattening or carbon build-up that leads to under-extrusion. The jump is worth it whenever prints start showing gaps on retractions or the filament path feels rough, restoring consistent flow without changing the hot-end geometry. Printers using different tube dimensions or direct-drive extruders without a Bowden section cannot use this part.