Plated Copper ¶
These are the latest addition to the E3D ecosystem and provide an increased thermal conductivity. The nickel coating here has low surface energy which reduces plastic adhesion, and has potential to increase flow rate. Copper alloy also performs better at higher temperatures than other nozzles. Great for sticky materials like TPUs and PET-Gs as well as extreme temperature polymers like Ultem.
General purpose, low cost, great for printing materials that don't have anything abrasive in them. Brass has a great balance of properties; thermally conductive, machines precisely and easily even with very small nozzles (see [V6 0.15mm High Precision Nozzles]), doesn't corrode or pit so retains a smooth surface finish for cleanly laying down extruded filament.
Vulnerable to abrasive erosion by more exotic filaments like carbon-fibre filled materials, metal powder filled materials and glow in the dark. Can be damaged by nasty head crashes with things like bulldog clips and glass. Using a wire brush on a brass nozzle will cause wear over time.
Hardened Steel ¶
Designed to resist the abrasion of materials filled with abrasive particles which act like liquid sandpaper on your nozzle. Carbon-fibre is a particularly abrasive and well known example for which these nozzles are ideal. Materials filled with metal powders can also be abrasive, as can glow in the dark pigments. Hardened steel nozzles are nearly impervious to wear and should last as long as your printer. Hardened steel nozzles are also very resilient to being damaged by things like crashing into glass, bulldog clips or getting mangled when you're too lazy to find the correct size 7mm spanner and use pliers instead, we know you do it. You can use a wire brush to clean a hardened nozzle without damaging it.
Hardened steel is somewhat less thermally conductive than brass, however in our testing this does not seem to have a noticeable impact on actual performance and print speed. Probably because the limiting factor is the conductivity of the filament, not the nozzle. If you are experiencing under-extrusion when switching over from brass or copper, we recommend that you increase your print temperature slightly until the results are deemed acceptable. Hardened nozzles are brittle, it is extremely hard to break one but if you do manage, they tend to crack rather than deform. Hardened steel nozzles are so hard that they can score and damage even glass print surfaces if dragged across the surface with force.
See this blog post by E3D for more information on Hardened Steel Nozzles: https://e3d-online.com/blog/2015/09/09/i...
Stainless Steel ¶
These are for specific applications by popular request of certain customers, usually where there is a food or medical need and the other two alloys are not acceptable for regulatory reasons. We don't certify or make promises that these nozzles are suitable for these applications, as this is down to each users individual machine and process. Stainless is somewhat more abrasion and abuse resistant than brass, but not better than hardened. Stainless steel can be useful for some very odd chemically corrosive materials.