HOBNAIL (FOOTWEAR)

In footwear, a 'hobnail' is a short nail with a thick head used to increase the durability of boot soles.
'Hobnailed boots' have been used since antiquity for inexpensive durable footwear, often by workmen and the military. They are boots with hobnails, usually installed in a regular pattern, over the whole sole. They also usually have an iron horseshoe-shaped insert, called a heel iron, to strengthen the heel. They provide traction on soft or rocky ground, but they tend to slide on smooth hard surfaces.