Panels comprising a mechanical locking device and an assembled product comprising the panels

A set of wood fibre based boards comprising a first wood fibre based board having a first main plane and a second wood fibre based board having a second main plane, wherein the first wood fibre based board and the second wood fibre based board are provided with a mechanical locking device configured for locking a first edge of the first wood fibre based board to a second edge of the second wood fibre based board, wherein the locking device is configured to lock the first wood fibre based board to the second wood fibre based board at a corner of an assembled product, wherein the first main plane is essentially perpendicular to the second main plane, wherein the first wood fibre based board comprises a core comprising fibres arranged essentially parallel to the first main plane and the second wood fibre based board comprises a core comprising fibres arranged essentially parallel to the second main plane, and the mechanical locking device comprises:

• an edge section groove at the first edge of the first wood fibre based board, wherein an edge section of the second edge of the second wood fibre based board is insertable into the edge section groove for locking the first wood fibre based board and the second wood fibre based board together in a direction parallel to the first main plane;
• and
• a flexible tongue arranged in an insertion groove provided in the edge section groove, wherein said flexible tongue cooperates with a tongue groove provided at the edge section of the second wood fibre based board, for locking the first wood fibre based board and the second wood fibre based board in a direction parallel to the second main plane,
• wherein a first thickness of a core material of the first wood fibre based board between the edge section groove and an outermost surface of the first edge in a direction parallel to the first main plane is greater than a minimum second thickness of a core material of the edge section of the second wood fibre based board,
• wherein the edge section groove comprises a first wall and an opposed second wall, wherein the first wall is closer to the outermost surface of the first edge than the second wall is to the outermost surface of the first edge, the first thickness is measured between the first wall and the outermost surface of the first edge, and
• wherein the flexible tongue is displaceable in a first direction in the insertion groove during locking of the first wood fibre based board with the second wood fibre based board, the first direction forming a non-zero angle with the second main plane.