The Nock and the String Loop
The nock of an arrow is made of plastic and serves as the attachment point to place an arrow on a bowstring. Snap-on nocks lightly snap onto or grasp the bowstring to prevent unintentional separation of the arrow from the bowstring.
Prior to shooting, check nocks for cracks, nicks, or any other damage. A damaged nock may not absorb the energy from your bow properly, causing it to "dry fire."
A nocking point (nock locating device) is most popular on recurve bows, longbows, or bows that are not using a release aid for shooting. It can be as simple as a small wrap of string or as elaborate as a rubber and brass band pinched onto the string at the appropriate spot.
A string loop is often used as the nocking point when archers are using a release aid and are shooting short axle-to-axle compound bows.
In order to shoot consistently, the location where the arrow joins the bowstring must be the same with each shot and with all shafts. Proper placement of the nocking point or string loop is an important part of tuning a bow for the best arrow flight and accuracy.
Styles of Arrow Shaft Nocks
Two-piece arrow shaft nocking systems include a shaft insert (bushing) and nock that are made specifically for several types of arrow shaft materials (such as carbonfiber, aluminum, or aluminum/carbon-fiber combination).
This one-piece arrow shaft nock is made to fit directly over the swaged shaft.
Called a push-in or insert nock, this popular type of one-piece nock is inserted into the end of the arrow shaft and fits tightly inside the shaft so that glue is not needed.