Caulkin

A caulkin (or caulk; US spelling "calkin" or "calk") from the Latin calx (the heel) is a blunt projection on a horseshoe that is often forged, welded or brazed onto the shoe. The term may also refer to traction devices screwed into the bottom of a horseshoe, also commonly called shoe studs or screw-in calks. These are usually a blunt spiked cleat, usually placed at the sides of the shoe.

Caulkins or studs improve a horse's balance and grip over uneven or slippery terrain, allowing the animal to move better and jump more confidently in poor footing. Screw in calks are most often seen in speed sports, such as eventing, polo, and show jumping, although they are sometimes used for dressage. Forged caulks of various styles are more often seen on race horses and working animals such as draft horses and some packhorses and trail horses, though in some areas they are still seen on field hunters and other riding horses that have to work in all weather and require extra traction, such as police horses.

Traditionally, the of an elongated horseshoe (commonly not more than 1.75 inches or 45 mm) have tips bent at an acute angle opposite to the surface attached to the horses' hoof. Traditionally, a farrier employs a forge in hot-shoeing to heat the two heel prongs to red hot and bends them by hammering prongs over a right-angle to bend into an acute angle. Occasionally, another caulkin is on the toe of the shoe and integrally formed in the initial forging process

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