by SteveRosenberg@aol.com » Thu Jun 17, 2004 9:13 am
An "iron" is an old, but still used, measurement of the thickness of leather. It it still in common use by the shoe industry, usually for the thickness of the sole of shoes. One iron is equal to 1/48 inch, so a sole 3 Irons thick would be 3/48" or 1/16", which would be .0625". This unit is believed to have originated when a piece of iron of a known thickness was used as a guage for the thickness of leather. Today the unit is also used for the thickness of insoles, which are often synthetic being made from cellulose pulp in a paper mill. These synthetics are more compressable than leather so they usually run "heavy". For example a 3 Iron synthetic would typically be around .070".