Set of panels comprising a locking device

A set of panels, such as building panels, comprising a first panel and a second panel and a locking device for locking a first edge portion of the first panel to a second edge portion of the second panel, wherein the first and second panels comprise a front side and a rear side, a normal of a main plane extending along the front and/or the rear side defining a vertical direction extending away from the front sides of the first and second panels, wherein the locking device comprises a horizontal locking device and a vertical locking device, the vertical locking device comprising:

• a separate tongue arranged in an insertion groove of the first edge portion, the separate tongue comprising a polymer-based material and a longitudinal extension of the separate tongue extending along the first edge portion, and
• a tongue groove provided in, and extending along, the second edge portion, wherein in a vertically locked state of the first and second edge portions:
• an abutment member provided at a longitudinal end portion of the separate tongue cooperates with a stop surface of the second edge portion, and
• a locking portion of the separate tongue cooperates with the tongue groove, wherein, during locking, the locking portion is configured to be gradually inserted into the insertion groove along the first edge portion in a first stage, and in a second subsequent stage the locking portion is configured to be gradually inserted into the tongue groove along the second edge portion.