Nozzle sizes: when to move off 0.4mm

Almost every printer ships with a 0.4mm nozzle, and almost everybody leaves it there forever. For a lot of what people print, that is the wrong choice.

Go bigger for speed and strength

A 0.6mm nozzle lays down roughly twice the plastic per pass. Prints finish far quicker, walls come out stronger because each one is thicker, and it clogs much less with filled filaments. On functional parts you will struggle to see the difference in quality.

Go smaller only when you must

A 0.2mm nozzle gives genuinely finer detail on small models, and costs you enormously in time — often three or four times as long. It also blocks far more readily. Worth it for miniatures, rarely worth it for anything else.

Hardened or brass

• Brass conducts heat best and gives the cleanest results with plain PLA and PETG
• Hardened steel is essential for carbon fibre, glow-in-the-dark and wood-filled filament
• Abrasive filament will visibly wear a brass nozzle within a couple of spools
• Hardened steel conducts heat slightly less well, so add about 10°C

After every change

Nozzles are consumables, not permanent fittings. Change one and you must re-set your Z-offset, and if you have changed size, update the nozzle diameter in your slicer. Forgetting the second one produces baffling results that look like every other fault in the book.