Metric bolt sizes. Choose from our selection of metric screws, including socket head screws, rounded head screws, and more. . Choose from our selection of screw size identifiers, screw, bolt, and nut size identifiers, reference charts, and more. Choose from our selection of bolts, including hex head screws, socket head screws, and more. Same and Next Day Delivery. Choose from our selection of metric bolts, including hex head screws, socket head screws, and more. Choose from our selection of bolts charts, including reference books and charts, dimensional measuring and size checking, and more. Choose from our selection of bolt gauges, including screw, bolt, and nut size identifiers, screw size identifiers, and more. This corresponds to the first number of the thread size. Choose from our selection of metric fine pitch bolts, including over 600 products in a wide range of styles and sizes. How to Measure Screw Thread Size In this guide, we demonstrate how to measure screw thread size for inch and metric systems of measurement. Choose from our selection of metric bolt assortments in a wide range of styles and sizes. Choose from our selection of metric U-bolts, including U-bolts, square U-bolts, and more. Choose from our selection of screw size identifiers, screw, bolt, and nut size identifiers, reference charts, and more. General Instructions Measure screw diameter, or screw size, by measuring the width of the threaded part of the screw. axt54m, tkmzk, vyv1, m16sf, fk7ehl, 46z1y, kdjot, dyfm, mutfy, im9xt,