Hotend Throat make a pathway for filament go from cool zone to hot zone, The inner size for insert filament must be perfect fit for the filament you are using, the inner hole is too big, the filament will jam on the hot zone, the filament will not be able to come out from the nozzle. The throat come with different size, different length, different size thread, all metal or with PTFE tube. Different type of the throats has different usage. The throat, hot block and nozzle must be secure tight to make sure the melted filament will not be able to come out from the gap between the throat and nozzle.
The Throat with PTFE tube means the PTFE tube inside of the metal throat, The advantage of using PTFE tube is making filament moving smoothly and easily, which is good for PLA Filament. But the disadvantage for PTFE tube is the limitation for the temperature. You cannot set the temperature too high, otherwise the PTFE tube will melt and sticky and make the hotend jammed.
The Throat with All metal means the throat was fully metal which support higher temperature. All metal throat is good for higher temperature filament such as ABS, PETG, Carbon fibre. Etc.
This Threaded MK8 throat is for 1.75mm filament. And it made from good quality stainless steel. 45° degree on the insert area, make sure filament loaded properly and smoothly. This throat will fit on M6 heat sink and heat block.
Material: Stainless steel
For 3D Printer 1.75mm Extruder; MK8
Radiating end thread: M6
Heating end thread: M6