What is a nock in archery?
A nock is the slotted fitting, usually molded plastic, at the back of an arrow that clips onto the bowstring. The word also describes the string grooves at a bow's limb tips. To nock an arrow means to place it on the string, with its shaft supported and its fletching correctly oriented.
What the arrow nock connects
The arrow nock holds the arrow on the string during the draw and receives the string's force during the shot. Its groove must match the diameter of the center serving, the protective thread wrapped around the bowstring.
The nocking point is a separate term: it is the location where the arrow sits on that string. Moving a nocking point changes arrow position. Changing a nock can change string fit, weight and fletching orientation.
Which nock type fits your arrow?
- Push-in nocks fit inside a shaft or a fitted bushing. Match the exact shaft and component specification.
- Pin nocks fit over a metal pin installed in the shaft. The pin can help protect the shaft end from another arrow, but damage is still possible.
- Glue-on nocks fit a prepared taper, often on wooden arrows. Their alignment depends on correct installation.
- Some nocks fit over the outside of a shaft. These require the matching shaft diameter and approved component system.
A nock that looks close can still be the wrong size. Use the arrow manufacturer's compatibility chart. Do not glue a press-fit nock to compensate for a loose fit unless the manufacturer explicitly specifies that method.
How should a nock fit the string?
It should clip on securely and release without excessive force. An arrow falling off under its own weight is too loose; a nock that binds hard on the serving also needs attention. Use the nock maker's fit check with the bow undrawn and the arrow directed safely.
Check several arrows. A worn nock can fit differently from a new one, and damaged serving can change the fit along the string. Use a compatible groove size or have the serving corrected. Heating, squeezing or filing a nock can weaken it.
Leave the nock room between its locating ties so they do not pinch it as the string angle closes at full draw. If the arrow lifts off the rest during the draw, stop and have the fit and spacing checked.
Inspect the rear of the arrow
After a close group or a rear impact, inspect the nock, pin or bushing and the shaft underneath. Replace a cracked, split or visibly distorted nock. A fresh nock does not make a damaged shaft safe to shoot.
Check that the nock is fully seated and its orientation gives the fletching clearance. On the bow itself, limb-tip nocks hold the string loops. A chipped groove or damaged loop needs inspection before the bow is used again.
Questions
Are arrow nocks universal?
No. The shaft connection and the string groove are separate fit requirements. Two nocks may fit the same shaft but have different groove sizes, or share a groove size while fitting different shafts. Check the exact arrow model, any pin or bushing, and the serving diameter before ordering replacements.
Can a damaged nock cause a dry fire?
A damaged or poorly fitted nock can fail to keep the arrow connected to the string. The bow may then release much of its energy without properly driving the arrow, risking bow damage and injury. Stop using any arrow with a suspect nock and inspect the complete rear assembly.
Is a nock the same as a D-loop?
The nock belongs to the arrow. A D-loop is a short cord loop attached to a compound bowstring for a mechanical release aid. The arrow still clips onto the served string between the loop attachments. Check the nock for string fit and the loop for wear where the release hooks on.