1 tape measure: Used to measure length.

2 steel ruler: It is a common measuring tool for measuring length, outer diameter and inner diameter.

3 iron angle ruler: Used to mark or check the perpendicularity of the measured object.

4 iron square: It is used to measure whether the measured plane is horizontal.

5 calipers: It is a kind of commonly used measuring tool, which can not directly see the size figures, so it must be used together with the steel ruler. Calipers are used to measure the outer diameter and inner diameter of sand mold (core), groove width, etc.

6 wet sand hardness tester: It is used to measure the surface hardness of sand mold (core). Generally, the hardness of sand mold after compaction is 70-80, the surface hardness of sand mold with high compactness is 85-90, and the hardness of sand core is 70-80.

The hardness of wet sand mold is expressed by the depth of steel ball being pressed. When the steel ball is pressed into a depth of 0.05mm, the hardness value can be read directly from the pointer of the hardness tester.