Made from heavy gauge stainless steel, and used for measuring the gauges of steel wire and hot and cold rolled sheet steel. Metric dimensions are recorded on one side and SWG (Standard Wire Gauge) marking on the other.SWG - mm - inches 36 - 0.19 - 0.0076 35 - 0.21 - 0.0084 34 - 0.23 - 0.0092 33 - 0.25 - 0.01 32 - 0.27 - 0.0108 31 - 0.30 - 0.0116 30 - 0.32 - 0.0124 29 - 0.35 - 0.0136 28 - 0.38 - 0.0148 27 - 0.42 - 0.0164 26 - 0.46 - 0.018 25 - 0.51 - 0.02 24 - 0.56 - 0.022 23 - 0.61 - 0.024 22 - 0.71 - 0.028 21 - 0.81 - 0.032 20 - 0.91 - 0.036 19 - 1.02 - 0.04 18 - 1.22 - 0.048 17 - 1.42 - 0.056 16 - 1.63 - 0.064 15 - 1.83 - 0.072 14 - 2.03 - 0.08 13 - 2.34 - 0.092 12 - 2.64 - 0.104 11 - 2.95 - 0.116