1. The 2020 Extrusions are perfect for DIY, such as building the 3d printers and so on. 2. These high quality 4040 Aluminium Extrusions form a perfect solution for custom machine frames, workstations, prototyping, guarding and many more purposes. 3. The extrusion are a great framing material as they are adjustable and can hold nuts on all 4 Grooved Surface sides.There are a few things you need to keep in mind when selecting a t-slot profile series for your project. Before you choose a profile series, think about the nature of your project and about what size, strength, color, weight and shape you will need.