Parts of an Arrow
Arrows have four parts.
Shaft: The long part of the arrow. Every arrow shaft has a degree of stiffness called spine, which means resistance to bending. Bending, known as "archer’s paradox," occurs when an arrow is released from the bow. The forward thrust of the string causes the shaft to bend in one direction and then bend in the opposite direction as it speeds downrange. Spine strength must be matched to bow draw weight. If your arrows are too lightly or heavily spined for your bow, the "archer’s paradox" movements will be extreme, resulting in poor arrow flight and loss of accuracy. Arrow manufacturers publish selection charts that match bow weights to proper arrow spine.
Fletching: The plastic vanes or feathers on an arrow. Fletching creates wind drag and also can cause the arrow to spin similar to a rifle bullet, providing stability and accuracy in flight. Fletching is made up of three or more vanes or feathers. One of the feathers will be a different color and is called the "cock" feather. The remaining feathers are referred to as the "hen" feathers.
Arrowhead: The point of the arrow. Many different kinds of arrow points are available, each with a different purpose and advantage.
Nock: A slotted plastic tip located on the rear end of the arrow that snaps onto the string and holds the arrow in position. There is a certain point on the bowstring, called the "nocking point," where arrows are nocked. Fine tuning of this location, by moving it up or down the bowstring, is usually required.