Abstract: A yieldable mine post, made of metal and in telescoping form. The post comprises a pair of mutually telescoping metal post lengths, one being slotted to receive selectively a chosen wedge for forced insertion within the slot to spread apart one of the post lengths, as to its diameter, whereby to increase surface friction between the post lengths and, thereby, the frictional resistance offered to progressive incremental displacements of one post length relative to the other in response to the downward movement of a mine roof supported by such post and further to cause resistance to sliding by forcing the outer post length to deform elastically outward and the inner post length to deform elastically inward, thus generating a "friction bubble" of "friction envelope" which progressively moves down the zone of pipe overlap.