The calibration method research on pitch diameter of large-size serrated thread gaugeZhang Bo Qu ChaoqingShanghai Institute of Measurement and Testing TechnologyAbstract:Currently,there exist many calibration methods for pitch diameter of common thread gauge,such as the three-needle method,image method,axis cutting method,the side-lay method and the ring method and so on.However,there is no uniform method for some largesize special thread gauge（e.g.serrated thread gauge）.This paper presents a practical solution for such pitch diameter calibration of special thread gauge,which has been veri？ed in practical application.[著者文摘]