How to make a corner connection between three square profiles

Using this method, you can join three pipe elements in one corner. The result is a spatial structure that provides maximum strength, an attractive design and a long service life. Double corner joints are widely used in the installation of supporting metal structures, the manufacture of tables, cabinets and other products.

Will need

In order to properly prepare the edges of the workpieces to be joined, we need to stock up on the following materials and tools:

a piece of profile square pipe;
pendulum saw with rotating table;
metal square;
regular marker;
a clamp of a suitable size and configuration.

The process of preparing the edges of workpieces for joining

We begin the work by cutting three blanks of the same length from a previously prepared square profile pipe on a pendulum saw. Then, using a metal square and a marker, mark a 45-degree angle at one end of each of the three pipe elements.
Next, we turn and secure the work table of the pendulum saw for cutting at an angle of 45 degrees, place the workpieces with angular markings on it one by one, clamp it with a clamp and make the first cut according to the markings. By the way, the markings in the presence of an adjustable table at the pendulum saw are of a control nature.

After this, we turn the workpiece 90 degrees, make the following markings and make the second cut.

We get a unique shape for the end of the profile pipe. We process the two remaining blanks in the same order. It wouldn’t hurt to treat the edges formed as a result of cutting with a file or sandpaper to remove burrs and minor defects.
Now we lay two blanks of the profile pipe on a horizontal surface so that they form a right angle in plan, and their corresponding edges, formed after two cuts, coincide.

Finally, we install the third workpiece on top into the kind of contact socket formed by the two blanks.

If the marking and cutting were carried out with sufficient accuracy, then all three elements of the profile pipe will fit together in one corner without noticeable gaps.

All that remains is to somehow connect them. In our case, this is most easily accomplished by welding, although other options are possible, such as soldering, riveting, etc.