An emasculator is a tool used in the castration

Castration

Castration is any action, surgical, chemical, or otherwise, by which a male loses the functions of the testicles or a female loses the functions of the ovaries.-Humans:...

 of livestock

Livestock

Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...

. Its function is to simultaneously crush and cut the spermatic cord

Spermatic cord

The spermatic cord is the name given to the cord-like structure in males formed by the ductus deferens and surrounding tissue that run from the abdomen down to each testicle.-Contents of spermatic cord:...

, preventing hemorrhaging while still detaching the testis from the animal.

The blade is always on the side of the emasculator with the nut that holds the blades in place, and should always be placed adjacent to the testis ("nut against nut"), so that the crushing clamp occludes the spermatic artery

Artery

Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....

, preventing life-threatening blood loss.

The ratchet (visible on the handle) allows the emasculator to be locked in the "closed" position for the 2 – 3 minutes required for primary haemostasis to occur.

The ends of the "clamp" are rounded and guarded to allow the emasculator to be placed over the testis and spermatic cord without cutting, until pressure is applied.