M4 x 16 Hex bolt for 3D printing, PA / PET/ POM

thingiverse

Many bolt / screw designs are not fit for 3D printing. Aside to the required tolerance related to the plastic/plastic friction, designs made with thread tools/apps or 1:1 copies of steel bolts are not working or the parts printed fail at low torque. One the main issues are sharp corners / edges and thread design that are not printable in relation to nozzle size / extruded filament diameter and printing method. Printer/filament/nozzle settings are rather significant, but with a weak design, there is a inherent failure to be expected. This design DIN 933 & ISO4017 is made from scratch with specific focus on the threading ending near the bolt head. Unlike many designs where threading suddenly stops or fade in straight direction (not following the pitch angle) the local forces on the material become very high when final torque is applied. This M4 bolt has a fading thread in the direction of the pitch. This is especially important when producing the bolt with 3D FDM technology.