A cutter insert assembly for a drill bit for boring into the earth, comprising a super-hard structure clampable to a support body by means of a clamp mechanism; the clamp mechanism comprising opposed or opposable compression members connected or connectable by a tension member capable of sustaining a clamping force between the compression members when the cutter insert assembly is in a clamped condition, in which condition the compression members exert opposing compressive forces on the super-hard structure and the support body, operable to clamp the super-hard structure to the support body, and in which condition the cutter insert assembly is self-supporting and capable of being mounted onto a drill bit body.