The present research is focused on the behavior of a type of joint between hollow sections. A theoretical model is created with the finite element method simulating a beam to column joint. The member which acts as the beam or as the brace of the joint (bi) is the same type of section with the other one act as the column or the chord (bo). Both members are square hollow sections. Firstly, the effect of the shear force due to the bending moment is examined with additionally the effect or the geometric ratio (β = bi/bo) and the thickness ratio (τ = ti/to) in the resistance of normal type joint. According to the parametric analysis followed, the design resistances of these types of joints are compared to those mentioned to EC3 and those proposed of the research study worldwide in the same type of joints under axial loads. Joints are classified according the pre-mentioned limits for open sections and the resultant moment-rotation curves. An experimental study of these normal joints is made. Joints of “X” type in scale 1:1 and geometric ratios β = 0.66 and β = 1.0 are examined including 4 moment type joints. In sequence, the previous type of joints are examined with the chord-column member rotated by 45o consisting a “bird-beak” joint. With the same parametric analysis the effect the geometric ratio (β = bi/bo) and the thickness ratio (τ = ti/to) in the resistance of this new type of joint is examined. The results obtained are compared to those for normal joints and classified according to their strength and rotational stiffness. A formula is proposed for the design resistance of these types of joints. The behavior of these theoretical models which are created with fem is also compared with the experimental results of “b-b” “X” type joints in scale 1:1 and geometric ratios β = 0.66 and β = 1.0 including 4 new moment type joints.