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.

1. Specification: 100*100-3000*6000 (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.

Type ( mm )	Precision Grade ( μm )
	0	1	2	3
100 ×  100	4	8	16
200 ×  100	5	10	20
200 ×  200	5	10	20
300 ×  200	6	12	24
300 ×  300	6	12	24
400 ×  300	6	12	24
400 ×  400	6	12	24
500 ×  400	6	12	24
600 ×  400	7	14	28
600 ×  500	7	14	28
800 ×  400	8	16	32	80
800 ×  600	8	16	32	80
900 ×  600	8	16	32	80

Typemm	Precision Grade ( μm )
	1	2	3	Final machining
1000 ×  750	18	36	90
1000 ×  1000	20	39	96
1200 ×  1000	20	39	96
1500 ×  1000	24	48	120
2000 ×  1000	26	52	129
2000 ×  1500		56	140
2000 ×  2000		60	152	230
3000 ×  1000			168	248
3000 ×  1500			174	254
3000 ×  2000			184	275
4000 ×  2000			219	310
4000 ×  3000			240	360
6000 ×  3000			308	460