The National Machine Taper includes a self holding series and a steep taper series. Thread Check Inc. lists gage data for the steep taper but can quote both series on request. The tapers numbered 10, 20, 30, 40, 50, and 60 are designated as the preferred series. The tapers numbered 5, 15, 25, 35, 45, and 55 are designated as the intermediate series. All standard taper ring gages are manufactured per ASME/ANSI B5.10 Class Z unless otherwise specified. Thread Check Inc. designs and builds tapered ring gages for a wide range of industries and applications. Other types of tapers include medical luer tapers, Cat V Flange Tapers and Steep Machine Tapers.