A rotary cutting tool includes a cutter body, a coolant cap, and a retaining ring for removably securing the coolant cap to the cutter body. The coolant cap includes an outer surface, an inner surface and a generally cylindrical outer surface extending between the outer surface and the inner surface. The retaining ring is disposed within a retaining ring notch of the cutter body such that the outer surface of the coolant cap contacts the retaining ring when high pressure coolant is introduced into the cutter body to removably secure the coolant cap to the cutter body.