The coupling profile is used for corner formation in an inside room for fixing glass or other wall plates and is made of plate the corner angle for the connected profiles being between 15 and 175 degrees. The profiles are fixed to each other at the corner by plate or stay bolts. For the vertical connection of profiles a threaded bar is enclosed in a tube, the profiles resting on the five ends of the tube as well as on the plates. The edges of the plates inserted in the profiles forming a corner have a ground finished surface, so that the sum of the two plate edge angles is equal to the corner angles of the profiles. This sum is even in the range of 15-175 degrees. The thickness-width ratio for the profiles is from 1:0.8 to 1:10.
