Abstract: A weld gage includes a gage body having a front gage plate and a back gage plate disposed in parallel facing relation to the front gage plate with a gap formed therebetween. The front gage plate has at least one kind of metric graduations provided at prescribed positions on an outer surface thereof, whereas the back gage plate has inch graduations at positions corresponding to the positions of the metric graduations of the front gage plate on an outer surface thereof. A slide scale is disposed between the front gage plate and the back gage plate for sliding movement. An angle-measuring plate is pivotally disposed between the front gage plate and the back gage plate.