Making Out Surface Plate can be made into the rib type or box type, and its working surface could be rectangle, square or round. Additionally, the working surface are allowed to have V or U-shaped grooves, round holes, slot holes. Etc. A surface plate is a solid, flat plate used as the main horizontal reference plane for precision inspection, marking out (layout), and tooling setup. The surface plate is often used as the baseline for all measurements to the workpiece.
划线平台的生产工艺流程基本是：
Technological process of production of Making Out Surface Plate:
一、铸铁平板毛坯：按技术要求制图纸、按图纸制作模型、配料、造型、烘干、浇铸、落沙、清理、检验毛坯的各部位；热处理毛坯，时效处理，其目的是降低铸件内部的应力，防止机械加工后的变形。
三、铸铁平板工件调平、人工刮研、检验科检验； 四、铸铁平板的外观处理、喷漆、包装、入库。 铸铁平板的精度也可以说是铸铁平板的平面度：铸铁平板一般精度可以分为0级、1级、2级、3级。铸铁平板的精度标准在《中华人民共和国机械行业标准》JB/T 7974—2000里可以查到。选用精度标准时一般根据使用情况酌情而定。3级精度以上的铸铁平板用做检验、划线、装配等使用，4级精度以下的铸铁平板一般用做铆焊等使用。
1. Rough casting:
Make drawings according to the technical requirements-Making mold as per the drawings-Prepare material-Modelling-Filling sand-drying-casting-Surface cleaning -Casting parts testing.
2. Heat treating and aging treatment, to reduce the internal stress of castings and to prevent it from deform after machining.
3. Rough machining:
Visual Inspection-Marking-Machining -Final inspection and test.
4. Precision finishing:
Leveling -Scraping- Inspection and testing.
5. Final finish:
Painting,-packing -deliver to warehouse.
The accuracy of the Cast Iron Surface Plate refers to the deviation from flatness of the working surface and it shall be classified as Grade 0,1,2,3.