Building panels including a first and a second panel and including a locking device. The locking device includes a tongue and an edge groove provided in the second panel and the first panel, respectively, wherein the tongue and the edge groove are configured to cooperate with each other for locking a first edge portion of the first panel to a second edge portion of the second panel in a first direction. The locking device further includes a separate tongue provided in an insertion groove and a tongue groove configured to cooperate with each other for locking the first edge portion to the second edge portion in a second direction. A length of the tongue groove along an edge portion may be smaller than a length of the edge portion. A length of the insertion groove along an edge portion may be smaller than the length of the edge portion.