Threaded Holes in Machined Prototype Parts

Proto Labs’ First Cut CNC machining service provides the ability to easily add threaded holes to your plastic and aluminum parts. Our service supports UNC and UNF threads from #2 up to 1/2", and metric threads from M2 to M12. Because of the lack of standards between CAD packages for specifying threads, we decide where to put threads by looking for holes that could be pilot holes that are suitably oriented. Don’t model in internal threads; it will confuse First Cut’s pilot hole finder. Our process uses 3-axis milling, so holes can only be milled and threaded if they align with one of the three cardinal axes.

When you receive your FirstQuote®, the interactive quote’s 3D display will show a graphic of your part and a list of threadable holes. The fast, easy way to assign threads to holes is to use the “options” dropdown to assign our best guess thread to each hole (you pick UNC, UNF, or metric). Or to individually tweak each hole, clicking on a listed hole in the table will prompt the display to zoom in on that hole and drop down a menu of threading options. You can also move from hole to hole using the “previous” or “next” buttons. When finished making selections, click on the “save current selections” button to complete the process. If your firewall prevents you from downloading the interactive viewer, a 3D PDF is also available. The PDF is not interactive, but selections can be made in FirstQuote. (This approach is as effective as interactive ProtoView, but not as much fun.) Once you have placed your order you will receive, by email, an order confirmation which includes your selected thread sizes. Be sure to review the confirmation for accuracy.

Click on the links below to read this full tip, and learn more about threaded holes capability at First Cut CNC machining service from Proto Labs.

Read full machining tip on threaded holes
See detailed information on modeling threaded holes
Demo a FirstQuote part sample with threaded holes