The first two of these manifolds are hyperbolic. The problem, I suspect, is that they are being specified as Dehn fillings on 1-cusped manifolds with essential tori. So one needs to pick a different knot in the closed manifold to actually see the hyperbolic structure. One way to force SnapPy to do this is to create a 1-vertex non-ideal triangulation and then use one of the edges there as the knot. For example: sage: M = Manifold('tri11.txt') sage: N = Manifold(M.filled_triangulation()._to_string()) sage: N.solution_type() 'all tetrahedra positively oriented' sage: closed = snappy.OrientableClosedCensus() sage: closed.identify(N) m038(1,2) The tri12 manifold is "m032(5,2)". I strongly suspect the tri13 manifold is *not* hyperbolic. Instead, I suspect it is a graph manifold where one piece is the figure-8 complement, since sometimes the volume appears to be 2.0988...