Here is another aluminum extrusion bracket that I designed as part of a CNC Mill that I am building. It connects 2 pieces of 2060 extrusion together, I used 85% infill for higher strength but adjust accordingly for your use. For mounting the bottom side (6 holes) to the extrusion it requires M5x10mm bolts and the vertical side (5 holes) uses M5x12mm bolts. If you are looking for other size extrusion brackets check out some of the other brackets I've made. I will be designing and uploaded more of these brackets as my CNC Mill comes along. Please share your makes on here I'd like to see what you all create! If you have any questions or issues please comment below, thanks!