Rotary cutting insert and tool having declined axial support surfaces

A cutting insert of a rotary drill tool for cutting metal comprising a head and a neck extending along a longitudinal axis, the head having an axially forward facing cutting region and the neck having an axially rearward facing mount region, at least the neck being arranged to be releasably mountable within a jaw of a support body, the head having generally axially rearward facing axial support surfaces projecting radially outward from the neck arranged for abutment with corresponding axial support surface of the support body, the support surfaces including a first decline orientation aligned relative to a plane perpendicular to the longitudinal axis such that a radially outer region of each said support surface is axially rearward relative to a radially inner region of each said support surface, said support surfaces including a second decline orientation being additional to the first decline orientation and aligned to extend in a circumferential direction relative to the plane perpendicular to the longitudinal axis.