4 Set 45 Degree/135 Degree Angle 2020 Series Aluminum Extrusion Profile Accessories，Aluminum Corner Brackets Profile with Mounting Screws and Nuts, (135 Degree)

Work as intended

Works, but difficult to setup

Works great

This is marketed as being for 20/20 extrusion profile, but it fits just fine in my 25/75 extrusion profile. The brackets are cast aluminum (painted black, not anodized), the sliding nuts are galvanized, and the bolts are carbon steel. That is, the hardware (or at least the bolts) will eventually rust on you if you keep this outdoors. The cutoff extrusion profile in my photos is 2575, not a 20 series extrusion. That being said, this also fit just fine in a scrap of 2020 I had lying around.The paint on this is alright. You can't scratch it with a fingernail or plastic, but it's pretty easy to scratch with a screwdriver. That's expected and not a big deal to me, but something to be aware of.Check out my pictures for the measurements of the sliding nuts if you don't know if this will fit your profile. The hole is M5 and the shap eof the nut means you have to slip this in from an open end of the extrusion. You can NOT simply drop this into the center of the extrusion somewhere. You have to slide it in from the end. That is mildly inconvenient at times, but the size of the sliding nut does mean it has more surface to surface contact than the Drop In type designs, so these should grip and lock down better.The nubs on the back of the brackets are undersized, so if your slot can fit the M5 bolt, the bracket will fit just fine.Overall, no complaints. These are exactly what I expected. I'm using these are part of a roofrack build and wanted something sturdy, affordable, and not overly bulky. These are just what I was looking for.

For joining two pieces of 2020 aluminum extrusion together at right angles, these are generally one of the strongest options. They also tend to be the option that is guaranteed to always be the closest to 90 degrees. For applications that are less exacting, I typically use the inside slot L corners (as they take no space and are essentially invisible), but they also tend to have more room to move around due to how they mount. These fit nice and snug and hold things right where they need to stay. And, if even more strength is needed, you can always add an outside corner brace afterwards, while relying on these to keep the angle more or less exact. Personally, I am using this set to reinforce the inside corners of a large CoreXY printer that otherwise has a bad tendency to flex more than I like, adding some needed rigidity and keeping all the angles perfectly square. I also like that this kit included both the T slot nuts and screws necessary for installation. This is even nicer if you aren't someone like me who keeps a lot of them spare on hand. I also appreciate that the screws are black oxide coated, so that they match the brackets nicely and make for a more finished final look. Overall, these seem to be lightweight, but strong and well made!

The bracket itself is well made but the included screws are too short and the nut is too big to be inserted into the rail and needs to be slid in from one end. Ended up using screws and nuts from another bracket.

JCSPBYL’s 2020 extrusion corner brackets provide good, accurate, and strong 90-degree connections between two pieces of 20x20mm aluminum extrusion pieces. The offering comes with 20 corner brackets and the necessary sliding nuts and screws to use them. The screws have wide heads so that an additional washer isn’t needed. However, a washer could be added for extra strength. The size of the sliding nuts and screws is M5. An M5 Allen wrench comes with the brackets.If you are constructing something using 2020 aluminum extrusions, you will eventually need a corner bracket. There are various styles of corner brackets; either internal or external L-shaped or the external triangular type like this offering. Of the two styles, the one offered here is the stronger since they act like a triangular gusset.These corner brackets are reasonably made and work well. When building your project these brackets can be very beneficial. Your project’s needs and cost constraints should drive your selection. If you require stronger and more rigid corners, this Is a good selection, If the strength isn’t needed, the L-style connectors are cheaper and may be the way you want to go.

I used two of these around my CR-10 mini and I was shocked how much it really stiffened up that frame on me. To the point where it looks alien seeing it move without the jitteryness of the machine anymore. I can't say this changed my print quality but it sure does make me feel better about using it. I have a few spare but i've moved onto an X1C that I don't see myself modding anytime soon.These are a great way to add some stability to any of the 2020 or 2040 or similar built machines. Good plate thickness. All of the parts were there, extra screws were appreciated. Couldn't ask for anything more out of this package.