# Need help meshing .step solids with threads **URL:** \ **Category:** General Questions\ **Created:** [March 21, 2023, 2:18pm UTC](https://prepomax.discourse.group/t/need-help-meshing-step-solids-with-threads/786 "2023-03-21T14:18:19Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![FdoLorenzo](https://avatars.discourse-cdn.com/v4/letter/f/5f8ce5/32.png) [@FdoLorenzo](https://prepomax.discourse.group/u/FdoLorenzo)\ **Post date:** [March 21, 2023, 2:18pm UTC](https://prepomax.discourse.group/t/need-help-meshing-step-solids-with-threads/786/1 "2023-03-21T14:18:19Z")
I have been trying to mesh the attached model, which is a two solid model that has a threaded section but the mesher in PrePoMax fails to complete the mesh. Any hints or ideas on how to set the meshing parameters. Your help is greatly appreciated F Lorenzo [3D-Loaded-3-21-23.pmx](https://prepomax.discourse.group/uploads/short-url/uCCHvmjTpLrw3sMqDF8JB9GEfou.pmx) (189.3 KB) ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [March 21, 2023, 2:42pm UTC](https://prepomax.discourse.group/t/need-help-meshing-step-solids-with-threads/786/2 "2023-03-21T14:42:13Z")
Which version of PrepoMax are you using ? I can’t open this file in the newest one. It says that it’s either from an older version or corrupt. ---
**Author:** ![FdoLorenzo](https://avatars.discourse-cdn.com/v4/letter/f/5f8ce5/32.png) [@FdoLorenzo](https://prepomax.discourse.group/u/FdoLorenzo)\ **Post date:** [March 21, 2023, 11:38pm UTC](https://prepomax.discourse.group/t/need-help-meshing-step-solids-with-threads/786/3 "2023-03-21T23:38:18Z")
I created and saved it using 1.40. I will recreate it using 1.35.1 and send it again. Here it is! Thanks! [3D-Loaded-V-1.35.1.pmx](https://prepomax.discourse.group/uploads/short-url/SNkkRMJbygG6YVmeJpcMaZDxpZ.pmx) (188.2 KB) ---
**Author:** ![lucas\_bueno](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/lucas_bueno/32/1168_2.png) [@lucas\_bueno](https://prepomax.discourse.group/u/lucas_bueno)\ **Post date:** [March 22, 2023, 1:05am UTC](https://prepomax.discourse.group/t/need-help-meshing-step-solids-with-threads/786/4 "2023-03-22T01:05:03Z")
Hi. I used mesh refinement of 0.5mm on each side of the threaded section. It mainly gave applicable mesh in this region. ![image](https://global.discourse-cdn.com/free1/uploads/prepomax/original/2X/6/64eba72b6dfb6e3cff5e4316835d27d9a4bf7bc8.jpeg) ![image](https://global.discourse-cdn.com/free1/uploads/prepomax/original/2X/3/3bee33538ccdc23c81f967ef8cf5850e3fb7fbad.jpeg) You should consider if using that many elements with contact settings can provide you with reliable and informative data. It will take hours to converge. Maybe using a model without the thread and using tie contact just to maintain the load path is a nice approach. After this, using a threaded axisymmetric model may help you in the first stages of the product development. ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [March 22, 2023, 8:20am UTC](https://prepomax.discourse.group/t/need-help-meshing-step-solids-with-threads/786/5 "2023-03-22T08:20:14Z")
I see. I assumed that it was prepared in version older than 1.3.5. In such cases it’s usually just a matter of proper element size setting. If you set too large elements, the mesher may not be able to mesh smaller details. Lowering the global element size usually helps but is not necessary since you can use local refinement to save time by reducing mesh density in areas far from the regions of interest. The choice of the initial mesh size should be done based on the smallest relevant geometric feature and then one should carry out a mesh convergence study to make sure that there’s no significant (around 5%) difference in results obtained for meshes of different density. ---
**Author:** ![FdoLorenzo](https://avatars.discourse-cdn.com/v4/letter/f/5f8ce5/32.png) [@FdoLorenzo](https://prepomax.discourse.group/u/FdoLorenzo)\ **Post date:** [March 22, 2023, 1:04pm UTC](https://prepomax.discourse.group/t/need-help-meshing-step-solids-with-threads/786/6 "2023-03-22T13:04:49Z")
Thanks very much Lucas! ---
**Author:** ![FdoLorenzo](https://avatars.discourse-cdn.com/v4/letter/f/5f8ce5/32.png) [@FdoLorenzo](https://prepomax.discourse.group/u/FdoLorenzo)\ **Post date:** [March 22, 2023, 1:05pm UTC](https://prepomax.discourse.group/t/need-help-meshing-step-solids-with-threads/786/7 "2023-03-22T13:05:46Z")
Thanks Jakub! I will keep in mind for future use. Best regards,