Are you clear about roundness, cylindricity, coaxiality and concentricity?

In the manufacturing industry, someone once estimated that there are more circular workpieces than flat workpieces, ranging from screws, nuts, gaskets, to cylinders and bearings. The application of circular shapes is indeed very high.

Measurement example of a circular workpiece.

Roundness

The extraction circle shall be confined to the tolerance zone between two coplanar concentric circles with radius difference t.

Straightness 

The edge extracted from the cylinder surface should be confined to the tolerance zone between two parallel lines with spacing t in the specified direction.

Flatness 

The distance is the region between two parallel planes of the tolerance value t.

Cylindricity 

The extraction cylinder surface shall be confined to the tolerance zone formed between two coaxial cylinders with radius difference t.

Concentricity 

The extraction center of the circle shall be confined within the tolerance zone formed by a concentric circle of diameter t with reference.

Coaxiality

The extraction axis shall be limited within the tolerance zone formed by a cylindrical surface of diameter t coaxial with the datum.

Perpendicularity

The extraction axis shall be confined to the tolerance area formed by a cylindrical surface with diameter t and perpendicular to the datum surface.

The extraction surface shall define a tolerance zone formed between two parallel planes spaced apart by t and perpendicular to the reference axis.

Circular runout (radial and axial)

Radial circle runout: In any section perpendicular to the datum axis, the extraction line shall be limited to the tolerance zone formed between two coplanar concentric circles with the radius difference t and the center of the circle on the datum axis.

Axial circle runout: On any cylindrical section coaxial with the reference axis, the extraction circle should be limited within the tolerance zone formed between two equal circles with an axial distance of t (cylindrical surface).

Full runout (radial and axial)

Radial full run-out: The extraction surface should be limited within the tolerance zone formed between two cylindrical surfaces with a radius difference of t and coaxial with the common reference axis.

Axial full run-out: The extraction surface shall be limited within the tolerance zone formed between two parallel planes with a distance t and perpendicular to the reference axis.