How To Measure Thread Size Diameter. Machine screws and cap screws can also be used to determine thread size. For screws with a hexagon head, such as b.
Use a ruler or tape measure to measure the inner diameter of the pipe. Nominal diameter is a more of a label than a size. How to measure threads 1.) first, use a combination o.d./i.d.
To determine the size of pipe fitting thread you need, first use a tape measure or scale to measure the inside diameter (id) of the threaded hole were you would like to install the fitting or the outside diameter (od) of your existing fitting as shown below.
Measure the outside diameter of the bolt threads using a vernier caliper. If it fits perfectly and sits snugly, then your hose size has a diameter of 3/4 inches. E is the pitch diameter you are trying to find m is the measurement you took To determine the size of pipe fitting thread you need, first use a tape measure or scale to measure the inside diameter (id) of the threaded hole were you would like to install the fitting or the outside diameter (od) of your existing fitting as shown below.