A support ring adapted to support a rupturable rupture disc member in a rupture disc assembly. The support ring includes an upper surface, a lower surface, a central aperture defined by an inner peripheral edge and at least one tear-initiating projection, and having a cutting means extending inwardly from the inner peripheral edge and below the upper surface and adapted to cut the rupture disc member. The cutting means includes a plurality a curved cutting portions, each of the plurality of curved cutting portions including an inner arc section extending closer to the inner peripheral edge than other portions of the curved cutting portion.