303 Stainless Steel Tip—303 stainless-steel-tipped nozzles don’t contain lead, so choose them when printing parts that may touch skin or food. However, they don’t transfer heat very well, which means they need high printing temperatures and don’t print as quickly as brass- or copper-tipped nozzles.

Opening Diameter—For opening diameter, consider whether you need precision or speed. The smaller the nozzle opening, the smoother the finish and the finer the detail, making these nozzles best for small and intricate parts. The larger the nozzle opening, the faster they print and less likely they are to clog, which is good for abrasive materials and large, strong parts. The most common opening to balance precision and speed is 0.4 mm.