If you do any kind of machining or part-making, you need to test the straightness and flatness of workpiece

and equipment installing. Like this Straight Edge from China,working surface made by skiving or precise

rubbing .Working environment temperature (20 ± 5) ℃.
Standard size are in stock. And we can make it as your special request for the specifications. If you are interested in, I 'll send you our catalogue.