Set of panels with a mechanical locking device

A set comprising a first panel with a first main plane, a first edge surface and a first panel surface, and a second panel with a second main plane, a second edge surface and a second panel surface, and a mechanical locking device with a junction plane (J), wherein the mechanical locking device is configured for locking the first edge surface of the first panel to the second edge surface of the second panel at the junction plane (J), wherein the first main plane is essentially perpendicular to the second main plane and the junction plane (J) is extending at a first angle (α) to the first main plane,

• wherein the mechanical locking device comprises at least one rod-shaped element at the first edge surface and at least one insertion groove at the second edge surface,
• wherein the rod-shaped element is configured to be inserted into the insertion groove in a locked position of the first and second panels,
• wherein the rod-shaped element extends at a second angle (β) from the first edge surface,
• wherein the insertion groove extends into the second edge surface at a third angle (γ) from the second edge surface,
• wherein the mechanical locking device further comprises at least one locking groove at the first edge surface or at the second edge surface and at least one locking part arranged in a locking part groove at the other of said first or second edge surface, wherein the locking part is resiliently retractable into the locking part groove and is biased to outwardly extend from the locking part groove, wherein the locking groove comprises at least one locking surface extending at a fourth angle (δ) from the first edge surface or from the second edge surface, the locking part is configured to be inserted into the locking groove and lock against the locking surface in the locked position, and the second angle (β) is different than the fourth angle (δ),
• wherein the first angle (α) between the junction plane (J) and the first main plane is about 45°,
• wherein the second angle (β) is within the range of about 30° to 60°, and
• wherein the mechanical locking device is configured to obtain the locked position by displacing the first panel relative the second panel in an assembly direction (AD), which is essentially parallel with the first panel surface and essentially parallel to a length direction (L) and/or axial direction (CA) of the rod-shaped element,
• wherein the second edge surface comprises a tongue, wherein said tongue comprises a first tongue surface and a second tongue surface and the first edge surface comprises a tongue groove configured to cooperate with the tongue in the locked position, wherein the tongue comprises the at least one insertion groove and the at least one locking groove, and wherein the tongue groove comprises the at least one rod-shaped element and the at least one locking part.