Abstract: A specialized clamp fits on to a screen frame in a screen printing press of the type having a frame clamping arm that pivots towards a platen during printing operations. The clamp has a passage located to receive a conforming register pin that extends from the platen to assure that the screen registers precisely at a predetermined area of the platen including in instances where the frame guide structure to the press itself may exhibit significant play. The clamp is initially engaged on the pin but not tightened enabling the screen frame to be shifted to register with the desired area of the platen. The clamp and clamping arm are then tightened to provide for repeatability of the registration. The clamp may then be used, during set up, to seat a succession of adhesive coated register pins at corresponding locations on a series of additional platens.