Gagemaker L.P. Inside Measuring Instruments

Inside measuring instruments are useful in measuring bores. Mitutoyo offers a mechanical and electronic instruments for bore measurement.* Both types offer two distinct measurement methods, two-point and three-point contact. Mechanical tools can further be divided by what type of scale used, direct reading or not. Deciding between a two-point (Bore Gage) and three-point method (Holtest or Digimatic Holtest) is the first step in determining bore measurement devices. Bore gages and Holtests have their own advantages and disadvantages. Bore gages can detect a more vivid geometric picture of the bore providing specific data on ovality, barrel, taper, and bell mouth. However, such information comes at the price of speed, as the inspection takes longer than the three-point method. With a MIN hold function, electronic bore gages can overcome excesses in inspection time. Holtests are a quick and easy measurement tools. While they are fast and for anyone, they give an averaged reading of the overall picture. So, any outlying reading may lead to unwarranted additional inspections.