Does a hollow cylinder in $\mathbb{R}^3$ have corners in the manifold sense?

Question

Does a hollow cylinder with end caps in $\mathbb{R}^3$ have corners? It is obvious that I need to check whether or not the edges are anywhere diffeomorphic to any open subset of the standard corner $[0,\infty) \times [0,\infty)$ in the (x,y) plane. I see that this doesn't seem to be the case, but an airtight proof escapes me.