PT Journal AU Gorog, A TI Influence of the Setting on the Result of Measuring the Roundness of the Cylindrical and Conical Surface SO Manufacturing Technology Journal PY 2022 BP 408 EP 413 VL 22 IS 4 DI 10.21062/mft.2022.055 DE Roundness; Systematic Error; Roundness Profile; Cylindrical Surface; Conical Surface AB When measuring roundness, accurately adjusting the measured part is very important. The axis of the measured part must be perpendicular to the section where the roundness is measured. If this fails, a systematic error will occur. It depends on the size of the inclination of the surface during the meas-urement. The paper presents mathematical relations to calculate the error when measuring roundness on a cylindrical and conical surface. It analyses the influence of the inclination and the parameters of the measured area on this error. The theoretically determined values are compared with the practical-ly measured roundness values. The error harms the accuracy of the roundness measurement. It af-fects the value of roundness, but also the roundness profile itself. It is explained that the mistake can not only increase but also decrease the measured value of roundness, in conclusion. ER