Gaosi Tools conical Stainless Taper Welding Gauge Test Ulnar Inch Metric (3-15mm) Made of high carbon stainless steel, miniature and light weight, pocket size. durable.New design. Welding taper gauge: 3-15mm (0.118-5/8 inch).Accuracy: 0.1mm/1/64" .The total length 185mm5.55 inch) inch Accurate taper throughout the length of the gauge makes it convenient for measuring diameters of small holes, slots etc. With imperial scales on one side , this is an ideal tool for die makers, machinists and on inspection floors. Polished, bright and clean without burr, rust laser engraved line and will not rub off . For accurately measuring of cylindrical bores, helping you to get the correct size for repair/replacement of wall wart cords, etc.