Wherever there is milkweed there will be Monarch butterflies. The monarch is widely distributed across North America, from Central America northwards to southern Canada, and from the Atlantic to the Pacific coasts.
The pitch diameter (often called the effective diameter) of a parallel thread is the diameter of the imaginary co-axial cylinder which intersects the surface of the thread in such a manner that the intercept on a generator of the cylinder, between the points where it meets the opposite flanks of a thread groove, is equal to half the nominal pitch of the thread.
A 1/2 - 24 UNF bolt is an American standard bolt 1/2-inch in nominal diameter, 24 threads per inch, with a united national fine thread. For both metric and standard bolts, the head size is the distance across the flats. For standard bolts, the head size is measured in inches or fractions of an inch.