Hobnail

In footwear, a hobnail is a short nail with a thick head used to increase the durability of boot soles.

Hobnailed boots (known in Scotland as "tackety boots") are boots with hobnails (nails inserted into the soles of the boots), usually installed in a regular pattern, over the sole. They also usually have an iron horseshoe-shaped insert, called a heel iron, to strengthen the heel, and an iron toe-piece. The hobnails project below the sole and provide traction on soft or rocky ground and snow, but they tend to slide on smooth hard surfaces. They may also have steel toecaps.