How To Measure Thread Size Diameter. If you don't know the pitch, choose coarse threads; (note that a compact version of this chart is included with the pee dee thread measuring wires.) 2.
Measure the outside diameter of the large portion of the thread at a; If you find yourself owning (or wanting) to own a lens with a 77mm+ diameter (or filter thread), expect to pay more for a filter than someone with a 67mm or lower. While the size m6 × 0.75 mm has a fine pitch.
Both the tpi (threads per inch) and od (outside diameter) of the thread are required for positive identification of thread size because several sizes have the same tpi.
If you find yourself owning (or wanting) to own a lens with a 77mm+ diameter (or filter thread), expect to pay more for a filter than someone with a 67mm or lower. The dimension in column 3 will be your nominal pipe thread size. Make sure you remove all fittings and accessories before you try to measure garden hose using this method. If the thread measures 0.5 it is not a.