Adding threaded features to your designs is easy, but doing it right is crucial to getting functional parts.
Common Errors in Designing Threaded Features
Many of the CAD files we receive that include threaded features make one critical error—designing to the major thread. Doing this can delay manufacture of your part. Worse, you could end up with a part that doesn’t work in your application.
Doing it Right: Designing to the Minor Thread
If your designs instruct us to mill the hole so that it’s the same diameter as the major thread, the hardware you use will never fit properly in the hole. At that point, you would have to use larger hardware, which might not be functionally acceptable or consistent with your design.
Instead, make sure that the threaded feature reflects the required minor diameter of the respective thread. There’s an easy way to do it, let SOLIDWORKS manage the process.
Working with the Hole Wizard
SOLIDWORKS’ Hole Wizard is incredibly helpful here. All you need to do is select the type of hole you want drilled, then specify the diameter of your tap hole by choosing the drill bit size. Designing to the minor diameter allows both our quoting and CAM package software to automatically identify the correct thread pitch and potential screw types.
If you want, you can also add a countersink by specifying an angle of 82, 90 or 100 degrees. The countersink specifications will carry over from the design model.
Threaded Features: A Quick Word of Caution
An important thing to remember is that threads on plastic parts wear out much more quickly than metal ones. You may want to consider incorporating special inserts in plastic parts to ensure longer part life.
For more helpful machining tips, download our CNC Machining Design Guide.