公开(公告)号：US20180335290A1

公开(公告)日：2018-11-22

申请号：US15962283

申请日：2018-04-25

Applicant: MITUTOYO CORPORATION

Inventor： Tatsuya NARUMI ,  Akihiko MATSUURA ,  Kentaro YANO

IPC: G01B3/30 ,  G01B5/20 ,  G01B21/04

Abstract: A step gauge includes: measurement blocks each having reference measurement surfaces; interval blocks each interposed between a pair of ones of the measurement blocks to keep a distance between the pair of ones of the measurement blocks at a predetermined distance, the measurement blocks and the interval blocks being alternately aligned one by one in one direction. The measurement blocks and the interval blocks each have a coefficient of linear thermal expansion of less than 0.03×10−6(1/K) and have through holes aligned in the one direction. The step gauge further includes a tie rod inserted in the through holes and countersunk screws respectively fixed to ends of the tie rod. The tie rod is made of a material having a coefficient of linear thermal expansion of less than 0.5×10−6(1/K).