Blade segment for refiner

A blade segment for a refiner for refining fibrous material, the blade segment comprising:

• a first end edge and a second end edge opposite to the first end edge in a direction of a longitudinal axis of the blade segment;
• a first side edge and a second side edge opposite to the first side edge, the first side edge and the second side edge extending between the first end edge and the second end edge;
• a refining surface comprising blade bars and blade grooves therebetween on a front surface of the blade segment;
• and
• wherein the first side edge and the second side edge each comprise at least two long edge portions which are inclined from the direction of the longitudinal axis of the blade segment and being connected by an elbow between each of said at least two long edge portions, the elbow having a first bend, a short edge portion which is shorter than the long edge portions, the short edge portion following the first bend and a second bend following the short edge portion;
• wherein an edge axis extends in the longitudinal direction from a first shoulder at the first end edge at the first side edge to a second shoulder at the second end edge at the first side edge, and at least one of the elbows of the first side edge has portions which protrude beyond the edge axis.