A self-drilling anchor for use in a friable material comprises a body
having an axis, a flanged rear end, a drilling front end and a generally
cylindrical portion therebetween having an outer surface with a thread
disposed thereon, wherein the body forks, beginning at a predetermined
distance from the flanged rear end, into a first leg and a second leg,
the first leg extending forwardly into a drilling tip and having a
generally rearward facing shoulder angled obtusely outwardly with respect
to the axis, wherein the body has an axial bore for receiving an elongate
fastener, the axial bore extending substantially through the flanged end
and the generally cylindrical portion and leading to the generally
rearward facing shoulder, wherein the anchor has a drilling mode wherein
the second leg nests behind the generally rearward facing shoulder of the
first leg, and an anchoring mode wherein the legs are pivoted apart from
one another.