Innovating Product Design with 3D Printed Threads and Screws

Screws and nuts have threads that convert rotational motion of their helical structure into linear motion. Rotation of the helical structure is achieved by grooves or ridges arranged spirally. Fasteners must be able to slide in and out of the groove when linear force is applied. For mechanical advantage, ease of use, and sometimes for aesthetic reasons, each type of fastener has specific leads and head shapes.

3D Printed Threads

Bolts, nuts, and screws are undoubtedly familiar to anyone who has been in charge of repairing or assembling something mechanical. A wide variety of hardware can be found in hardware stores around the country.

A 3D printer gives you more design freedom than any other technology. The filaments, custom threads, and screws are now more affordable, making them viable design options. You may require unique bolts and nuts of non-standard sizes if your product has enough tricky mechanical parts, as this could be solved by 3D printing.

Construction Process of 3D Printed Threads

Creating 3D printed screws and threads is not practical from a practical standpoint. There is no shortage of reliable, easy to access, and affordable metal fasteners; there is a vast supply that is readily available.

An important advantage of 3D printing fasteners is that they can be customized in an unlimited number of ways. In all likelihood, you are wasting your time unless you want to create a fastener with a custom-shaped and customized profile.

Metal, plastic, and rubber fasteners are typically used in threaded fasteners. Strong and corrosion resistant metals like steel and titanium are preferred. There are also products made from brass or bronze that has a higher electrical conductivity, as well as gold plated products.

Popular 3D Printer

By employing subtractive manufacturing methods, threading mills remove material until the desired shape is achieved. Due to the fact that 3D printing uses an additive manufacturing principle, the process is reversed. The fastener is formed by extruding filament onto a print bed rather than removing bits of material. While 3D printing can be done using a variety of methods, not all are the same.

An affordable and standard method of 3D printing is fused deposition modeling (FDM). Due to its dimensional stability, FDM is capable of producing smooth, high quality threads for plastic filaments. It is less efficient than other methods, like laser sintering and resin based methods.

Metal filaments are best manufactured with laser powder bed fusion and binder jetting. Similar to FDM, metal 3D printers extrude metal powder and wax binder, and further processing is required to remove the binder and produce the actual metal parts. The Velo3D Sapphire, which costs upwards of $500k, is on the higher end of the spectrum.

3D Printing Fastener Threads Basic Requirement

Layer Height

The layer height is another important parameter, which refers to the size of each layer. As part of the Z resolution, it represents the thickness of the layer. Layer height should be kept as low as possible for smooth operation. Smaller threads must be 3D printed in thinner layers; threads larger than half an inch require a .2mm layer at most.

A specific part can be done with more layers when the layer height is lower. The surface finish can also be improved with a higher number of layers.

There is a balance between fast turnaround and smooth results in many 3D printing companies. Layer height should always be set to the 3D printer's lowest setting, regardless of the thread type and shape.

Support Material

There is usually a support structure on the print bed of low-end 3D printers. Layers are added to a 3D-printed part during the printing process. Support structures and their orientation can influence the amount of material or filament used for printing since each layer builds upon the previous one.

To minimize the size of the support structure, it is best to 3D print the threads vertically. A smooth Surface Finish will happen if you don't remove support material from threads at the end of the process.

In addition to being wasteful, expensive, and not adding value, 3D printers that print standard-sized threads and screws are not cost effective. You can create a unique fastener with outrageous detailing when you 3D print screws, nuts, and bolts. 3D printing Applications in this situation can save time and reduce costs.

Post Processing

Only when excess materials need to be removed does post-processing become necessary. The support structure can be removed with a pick or pliers if the filament is plastic. 3D printing reduces the chances of support material getting into the threads by printing vertically. Materials can be difficult to remove from fine threads without damaging them.

For parts printed with metal powder, additional equipment is often required to ensure a fine finish. The wax binder must be removed with Wash-1, and the powder must be solidified with Sinter-2. Post-processing equipment is typically sold separately with most metal 3D printers, regardless of price.

Important Things to Consider on 3D Printed Threads & Screws

A small pitch and a small diameter make printing internal threads smaller than 4mm challenging. Using a tap wrench to cut the threads might be easier than 3D printing a hollow part.

There is nothing unusual about loose threads on a male fastener or too tight ones on a female screw. Creating small samples before printing larger parts is a good idea since some filaments shrink even during 3D printing.

To get online demonstration, watch the following video tutorial.

Video Source: Maker Tales

Decorative 3D-printed screws and fasteners, especially those with smaller threads, are usually made of plastic. Other than a small amount of mechanical support, they are not designed to carry weight. An aesthetic oriented part smaller than M6 may not be functional.

However, metal fasteners made from 3D printing are both functional and aesthetically pleasing. Toys, simple household items, etc., which have no moving parts or internal mechanisms, might be suitable for plastic 3D fasteners.