桥型平尺:按JB/T7977-99标准制造，材料HT250,工作面采用刮研工艺，是用来测量工件的直线度和平面度的量具，使用温度（20±5）℃
桥型平尺规格：(mm) 500×50      

                                     750×50        

                                     1000×50      

                                     1600×70      

                                     2000×80        

                                     2500×90   

                                     3000×100

                                     3500×100

                                     4000×110

                                     5000×110

                                     6300×120

                                     8000×120