Studded tires began to become common in the 1960s, and still hold a very strong position in the winter tire market. Studded tires come into their own on icy winter stretches of road, where the tires can dig in to find suprising levels of grip on even the most the slippery surfaces. Studded tires are a good choice for drivers with little experience of winter driving, as they smooth out changes in driving conditions.
New studded tires should be driven in for the first 400 or 500 kilometres by avoiding rapid acceleration, high cornering speeds and violent braking. The studs will then be able to properly settle into their holes and will function correctly for the lifetime of the tire. New studs can not be fitted to replace lost ones, as they will not stay in the holes formed in the tire. The stud holes are formed during the vulcanization process, by means of plugs in the tire mould. The stud holes in tires for heavy machinery are generally drilled after manufacture.
A winter tire can be recognised by the M&S mark, which indicates that it is suitable for use on snow (mud and snow). If you are wondering whether studded tires might be the best choice for you, you can read more here, and see whether studded tires or non-studded winter tires best suit your needs.