Abstract: A karate board includes a pair of pine board members equal in size to one-half of the karate board. A releasable edge connection includes similar channels firmly affixed to the joinder edge of each board. Each of the channels includes a connecting slot having a reduced neck portion. The abutting channel faces are planar with the reduced neck portions in alignment and a key extends through the adjacent neck portions with inner enlargements which firmly interlock the board members together. The channel members and the key member are formed of plastic which is slightly flexible and of a low friction coefficient. The outer edges of the abutting channel faces are rounded. The neck portions are circular with the axis in the abutting faces and the enlargements of the key are also circular to provide rolling surfaces.