How to Convert STEP Files to STL Format

The two most commonly used engineering 3D file formats are STL and STEP, each serving distinct purposes in various manufacturing processes. Rather than creating a new file from scratch in a different format, it’s far more efficient to convert between STEP and STL files as needed. In this article, we will explain which file format is required for the different manufacturing processes, provide guidance on how to convert your files, and offer insights into the importance of choosing the right format for each process.

STL and STEP files explained

STL or .stl — a specific file type used in 3D printers. Rather than containing the full CAD model data, .stl files only contain the model’s surface-level detail that is necessary for 3D printing.

STEP or .stp — Typically needed for CNC machining and injection moulding technologies. These file formats contain more detailed information than STL files, and they can be used to create models with multiple colours and complex geometries.

Easier to convert STEP Files to STL

Is it possible to convert STEP to STL? Yes, it is. In fact, starting with a model in STEP format and converting it to STL is often preferred for most design and 3D printing workflows. This is because STEP files contain rich, structured data representing the original CAD model, including solid geometry, assembly structure, and metadata, allowing for precise design iterations, modifications, and adjustments before converting to STL for 3D printing.

How to convert STEP Files to STL

Converting an STL file to STEP format allows you to transfer 3D models between different CAD software packages while retaining their geometry and structure. Here’s a step-by-step guide on how to convert an STL file to STEP:

Step 1 — choose a STEP-to-STL converter program:

• CAD Programs: If you’ve completed your STEP file in a CAD program like SolidWorks, Fusion360, Autodesk or similar, the process will be relatively similar. Navigate to the program’s file exporter option and export as “STL”. Alternatively, you can use the “save as” function to save the STEP file as an STL.
• Free Online Converters: If you don’t have access to one of the CAD softwares mentioned above or you no longer have a license, you can use a free or low-cost online converter to get the file type you need. Some free online converters you can try include MakeXYZ, ConvertCADFiles, and FreeCAD.

Step 2 — do necessary mesh repair:

• Check for Errors: Before converting, it’s essential to ensure that your STEP file is error-free. Some CAD models may have issues like gaps, intersecting faces, or non-manifold edges, which can cause problems during conversion.
• Repair Mesh: Use the repair tools provided by the chosen converter or a separate mesh repair software like MeshLab, Netfabb, or Mesh Mixer. These tools can help fix any issues with the mesh topology and geometry.

Is it possible to convert my STL file to STEP?

Yes, it is. Similar to converting STEP to STL format, you can convert your STL file to STEP through professional CAD programs like SolidWorks and Fusion360 or free online converters like FreeCAD, netfabb, Meshlab, and Mesh Mixer. However, it’s important to note that it can be more challenging, as converting STL files to STEP may lead to the loss of fine details and intricate features present in the original CAD model.

Nevertheless, it is still feasible to convert from STL to STEP when necessary, especially through making necessary mesh repairs and some manual adjustments like adjusting tolerances, refining surface geometries, and ensuring proper alignment of components to preserve important design elements.

Start manufacturing your CAD design

Have your STL file ready for 3D printing or STP for CNC machining? Simply upload your CAD file to HLH Rapid’s instant quote software, and within seconds, you’ll receive a quote. Select from a range of engineering-grade materials and surface finishes then place your order online to begin manufacturing immediately.