API螺纹高度测量仪，分为外螺纹、内螺纹、偏梯形螺纹高度测量仪，主要用于对API专有螺纹齿高的测量，使用前需要用齿高标准块校对，标准块需要单独购买。 API Thread Height Gages, Such as External、 Internal、Buttress-Casing Thread Height Gages, Measure the API thread height, need be preset with the Height Stardards. Sold separately from the gages