1. Specification: 100*100-3000*8000 (the special specification product can be manufactured according to the drawings from customers).

2. Usage: It is applicable to various inspections and benchmark planes for accuracy measurement. It can be used as the measurement benchmark for machine tool inspection and to inspect the dimension accuracy or running difference with the function of performing precise lineation. It is an inevitable tool during machine manufacturing.

3. Material and processing: The material is high strength cast iron HT200-300, and the rigidity of working face reaches HB170-240. It goes through twice of man work processing (man work anneal by 600° with natural validity of 2-3 years) in order to make the product stable in accuracy and good in grinding resistance.

4. Accuracy: It is in accordance with the procedure of state standard for measurement and inspection, which is divided into four levels of 1-4.