Abstract: A scribe/guide tool used as a compass and to layout stair stringers. The tool is also used in conjunction with a straightedge or a rule to function as a compass, and is most often used in pairs. A scribe means is removably inserted into the body of the tool. The tool includes a clamping means with smooth surfaces to affix the scribe/guide tool to another cooperating tool. A clamp element is moved up and down relative to the main body via a screw drive. Position indicating edges of the main body of the tool are tapered to a very narrow point to reduce the possibility of accumulated error when marking a workpiece with the tool as a guide.