All successful additive manufacturing projects start with, clearly, a digital model. Before any part can be printed, it first has to be created, and then shared and prepared using the appropriate file format. Learn more about 3D printing in general, in case you are still not sure how it all works.
Anyway, two of the most commonly used formats are STL and STEP. Both play an important role in product development. But they both also serve different purposes. Understanding how to choose the right file format is essential, as it can improve design accuracy, simplify collaboration, and reduce delays before production begins.
This means that you should get familiar with both formats. Understanding their strengths and limitations will help you select the one that best works for your particular project. So, what we are going to do now is help you get a better idea about both of these options and understand them clearly, in an effort to help you make up your mind on which one you may need. Let us start right away.
What Is an STL File?
We are going to begin with STL. This stands for Standard Tessellation Language, or Standard Triangle Language, and it is one of the oldest and most widely used file formats when it comes to 3D printing. Instead of storing the actual geometry of a particular part, an STL file represents its surface using thousands of small triangles that are interconnected. Those triangles work together to approximate the shape of the finished object.
This file is rather simple. And thanks to its simplicity, it has become the standard format accepted by pretty much every 3D printer and slicing software. As you can see at norraam.se, it appears to be the standard in additive manufacturing, and many workflows still export STL for print-ready files. It has been around for a long time, and it still clearly serves a great purpose.
What are the advantages of this file format, though? It offers several practical benefits. For one thing, it is widely supported, and easy to export from most CAD programs. For another, it is compatible with nearly all slicing software, and simple to transfer between systems. And then, it is well suited for preparing models for printing, and provides everything that is required to start the printing process.
Even though these are extremely popular, STL files still come with some limitations. They do not contain some important information, such as feature history, dimensions, material properties, assembly relationships, manufacturing tolerances and design parameters. They, instead, only describe the outer surface of the part. Furthermore, editing an STL file can be quite challenging, given that the original intelligence has been removed. So, even small modifications can require rebuilding portions of the model.
What Is a STEP File?
Let us move on to the STEP format now. This stands for Standard for the Exchange of Product Data. These files store complete three-dimensional CAD geometry instead of a mesh made of triangles. So, the model retains detailed engineering information that can then be used throughout the entire design and manufacturing processes.
What are the advantages of STEP files, though? There are several to consider. They retain accurate solid geometry, curved surfaces, feature information, assembly structure, precise dimensions, and high design accuracy. Plus, since the models remain editable, engineers can easily make changes without having to recreate the entire part. That kind of flexibility makes this format especially valuable during product development.
How to Choose the Right Option for You?
The answer to the question of which format is better for 3D printing depends on where you actually are in the process. For designing and modifying a part, STEP is usually the better option, as it preserves the complete CAD model. On the other hand, for preparing a finalised design for printing, STL seems to be superior, because it is compatible with nearly all slicing programs and additive manufacturing systems. Rather than choosing one or the other, many projects depend on both formats, used at different stages.
How can you choose the right one for you, then? Well, STL is the right choice when the design is complete and the part is ready for slicing. You should go for it if you are preparing files for 3D printing, and if no additional engineering changes are expected. The broad software compatibility is quite important here, and it is where STL shines.
STEP is often the better option when the design is still evolving and you are expecting engineering changes. Furthermore, it is the right move when multiple CAD platforms are involved, because it simplifies collaboration. Then, you should also go for it if tight dimensional accuracy is important and if the model may later be used for machining or for some other manufacturing processes. The flexibility they provide is essential when adjustments are necessary. Think about what you need for your project and then make your decision.
