When belting is purchased it is not necessary to uncoil it to determine its length. It may be measured in the coil in the following manner: To the diameter of the coil in inches, add the diameter of the hole in inches; multiply by the number of coils in the belt and multiply the resulting figure by .1309. The product will be the length of the belt in feet.
Fig. 142. - Pulley used for Rope Drawing.
Example. - How many feet of belt are there in a coil that is 22 in. in diameter? The hole is 4 in. in diameter and there are 48 coils.
the number of feet of belting in the coil.
If exact measurements are desired, it is necessary to get the average diameter of the coil and the hole, and also any fractional parts of a turn the belt makes in the coil.