Home » How to mate parts with threads in SolidWorks assemblies?

There are many mate options to choose from in SolidWorks, one that is quite useful is the “Screw” option from the mechanical mates section. This mate can be used to mate two parts whose threads are modeled. The steps to constrain two M10x1.0 fasteners are as follows:

  1. Fully constrain one of the two items, in this case, the nut is constrained to the origin.
  2. Set temporary axis visibility to on. Use the hide/show button in the graphics area and select view temporary axis.
  3. Create a new mate.  Select the coincident option and select both the axis of the nut and the axis of the bolt.  Use the mate alignment to set the bolt in the correct orientation.
  4. Create a section view cutting through the body of the nut/bolt. This will make the selection of the face in step 5 easier.
  5. Create a new mate.  Select the screw mate option from the mechanical window, and use faces representing the major diameter of the thread as the selections for the mate. Set the revolutions/mm to the pitch of the screw, in this case, 1rev/mm.

Once the mating process is complete, return to the full view of the model. The bolt can be tightened/loosened by clicking and rotating the bolt in the assembly.

Understanding the Screw Mate Option in SolidWorks


In SolidWorks, a screw mate is a type of mate that allows two parts to rotate relative to each other along a common axis, like a bolt turning in a nut. It is a special type of concentric mate that takes into account the helical shape of threads on cylindrical surfaces.

To create a screw mate in SolidWorks, you must first have modeled the threads on the parts you want to mate together. Once the threads are modeled, you can use the screw mate option in the Mate PropertyManager to create the mate. Here’s how to do it:

  1. Open the assembly and select the parts you want to mate together.
  2. Go to the Mate toolbar or use the Insert > Mate command.
  3. In the Mate PropertyManager, select the Concentric mate option.
  4. Check the “Screw” option to enable the screw mate option.
  5. Select the cylindrical surfaces on the two parts that you want to mate with the screw mate.
  6. Specify the direction of the threads by selecting a face or edge on one of the parts.
  7. Choose the thread type and size from the drop-down menus, or enter custom values if necessary.
  8. Adjust the thread engagement distance if needed, which determines how far the threads will screw in.
  9. Click OK to create the screw mate.

Once you have created the screw mate, you can test it by rotating the parts to see how they interact. You can also adjust the thread engagement distance or thread type and size as needed.

Note that the screw mate is a more advanced type of mate and requires careful attention to detail when modeling threads and specifying the mate parameters. It is also important to use the correct thread type and size to ensure accurate mating.

Tips for Accurately Modeling Threads in SolidWorks

  1. Use the Thread Tool: The Thread Tool in SolidWorks is specifically designed to create accurate thread models. Using this tool can save time and ensure the threads are modeled correctly.
  2. Choose the Right Thread Type: Make sure you choose the correct thread type (e.g., UNC, UNF, Metric, etc.) for your project. If you are unsure which thread type to use, consult a reference or specification.
  3. Know Your Dimensions: Accurately modeling threads requires knowledge of the dimensions of the thread, such as the pitch, major and minor diameter, and thread angle. Make sure you have this information before you start modeling.
  4. Model the Full Thread: Make sure you model the entire length of the thread, even if it extends beyond the surface of the part. This will ensure accurate mating and prevent interference with other parts.
  5. Use a Helix Sweep: A helix sweep can be used to create thread features on parts that do not have a circular cross-section. This is a useful tool for modeling threads on complex shapes.
  6. Avoid Over-Modeling: Modeling threads with too many features can slow down your computer and make it harder to work with the part. Use as few features as possible while still accurately modeling the thread.
  7. Test the Thread: Once you have modeled the thread, test it by mating the part with another threaded part or testing the fit with a physical sample of the mating part. This can help identify any inaccuracies in the thread model.

By following these tips, you can accurately model threads in SolidWorks and create successful screw mates. Remember to double-check your work and test the thread to ensure it is accurate before using it in an assembly.

How to Test a Screw Mate in SolidWorks

Once you have created a screw mate in SolidWorks, you will need to test it to ensure that the parts rotate correctly and that the thread engagement is accurate. Here’s how to test the screw mate by rotating the parts:

  1. Open the assembly that contains the parts with the screw mate.
  2. Select one of the parts that is mated with the screw mate.
  3. Click and drag the part to rotate it along the axis of the screw mate.
  4. Observe how the other part rotates in response to the rotation of the first part.
  5. Check that the parts rotate smoothly and without interference.
  6. Verify that the thread engagement looks correct, meaning the threaded surfaces mesh together properly.
  7. If the parts do not rotate smoothly or there is interference between the threads, adjust the screw mate parameters until the rotation is accurate.
  8. If the thread engagement is not accurate, adjust the thread engagement distance or thread type and size until it is correct.
  9. Test the screw mate by rotating both parts in different directions and observing how they interact.

It is important to test the screw mate thoroughly before using it in a larger assembly. This can help identify any issues with the thread modeling or screw mate parameters and prevent problems down the line. If you encounter problems, revisit the steps for creating a screw mate and adjust the settings until the screw mate works correctly.