What the standard defines
The ISO metric screw thread system defines thread profiles, nominal diameters and pitches. M6 names a nominal diameter of six millimetres, with the standard coarse pitch unless another is written. Two parts cut to the same designation screw together.
What it does not promise
No nozzle length or seat: hotend families differ in how far the nozzle reaches and where it seals. No material or temperature suitability, which depends on brass, steel or tipped construction. No interchangeability between hotends: an M6 nozzle made for one family can leak or sit wrongly in another. No torque or tightening procedure, which the printer maker provides.
What it works with
Hotend families, which set the full nozzle geometry. Orifice diameters, chosen freely within a family with a slicer change. Quick-change nozzle systems, which replace the threaded interface altogether.
Questions makers ask before buying
Are all M6 nozzles interchangeable?
No. Nozzles with the same thread differ in overall length, thread length and the shape that seals against the heat break. The hotend family decides fit.
Is the pitch always the same?
An M6 designation without a pitch usually means the standard coarse pitch; fine-pitch variants are written with the pitch. Nozzle makers state the thread they cut.
Last reviewed 15 September 2026