Abstract: A mold for forming a recycled rubber material under high pressure and temperature comprises a female mold member having a rectangular solid exterior and a pyramid cavity extending into the base thereof. A pair of opposed detents or latches are pivotally secured to each end of the female mold member, adjacent to a pair of slots extending into each end. The male mold member comprises a base plate from one side of which extends a pyramid member. To the opposite side a pair of parallel bars is welded, disposed to be received in the slots in the female member. With a charge of recycled rubber material disposed in the female member of the mold, the pyramid portion of the male mold member is placed in the mold cavity, and the two are compressed together by external means, creating very high pressure in the rubber material. The detents are pivotted to engage the bars, locking the mold members together and maintaining the high internal pressure without the external means.