Arrow Nocks

What a nock does, and what it has to fit

The nock is the plastic piece on the back of the arrow that holds it on the string. At the shot, the string shoves the arrow forward through the nock. So this tiny part carries the full push of the bow every single time. Archery 360 points out that it absorbs much of the string's energy at release.

A nock has two jobs that pull in different directions:

• Hold the arrow on the string while you draw, wait and aim
• Let go cleanly the instant the string moves forward

Every buying decision on this page comes back to those two fits. One fit is the nock to the shaft. The other is the nock to the string. The shaft side is a numbers problem. The string side is a feel problem, and you test it with your ears.

The table on this page shows the specs makers and Amazon listings state for each pack: the kind of nock, the shaft inside diameter it fits, how many come in the pack and, for lighted nocks, battery life, activation and color. The table marks values that come from the listing rather than the maker; a dash means neither states it.

What to look at when you buy arrow nocks

Fit the shaft's inside diameter, not the outside

The "Fits shaft ID" column is the most important number in the table. ID means inside diameter: the size of the hole in the back of the shaft. Press-fit nocks have a post that slides into that hole, so the post has to match the hole within a hair.

Common press-fit sizes and the shaft IDs they fit, per one lighted-nock maker's size chart:

• G: .165 inch
• X: .204 inch
• H: .233 inch
• S: .244 inch
• GT: .246 inch

Easton says its S, X, H and G letters describe a shaft's internal diameter and tell you which components fit. Easton calls S its "standard" diameter and G its "ultra-micro." Other makers borrow the letters, but not every maker uses them. Either way, the size on a nock pack is the hole it fits, not a measurement of the nock itself. So a nock labeled .244 doesn't measure .244 anywhere. It fits a .244 hole.

Quick math on why this matters: the gap between an S and a GT is two thousandths of an inch. You can't see that. The shaft can feel it. A nock that's one size off may push in and feel fine at home, then work loose at the range or split the shaft end. Read the inside diameter off the shaft maker's spec, then buy the nock that lists it. Your arrow's outside diameter is a different number and tells you nothing about nocks. (More on shaft sizes is on the hunting arrows page.)

Use the click test for string fit

The string side has its own vocabulary. The groove is the slot between the two "ears" of the nock where the string sits, and the throat is the opening the string snaps through to get there. Archery 360 treats groove and throat size as the thing to change when the fit is wrong, and notes that some brands sell the same nock with a large or a small groove.

Archery 360 describes the right fit simply. The nock should give an audible click as it snaps onto the string. Then a light tap on the string should knock the arrow off. It's the same feel as a good food-storage lid: you hear it seat, and it still comes off without a fight.

What goes wrong at each end:

• Too tight: the nock grabs the string at release, which hurts accuracy and makes the bow hard to tune
• Too loose: the arrow can fall off the string during the draw, which is unsafe

Here's a home check. Nock an arrow, point the bow straight at the floor and let the arrow hang. It should stay put. Then tap the string with one finger. It should drop. If it fails either test, Archery 360 suggests two fixes: re-serve the string to match the nock, or switch to a nock with a different throat size. Easton's tuning guide adds two details. String fit matters most on light bows, 30 lb and under. And for hunting, a slightly tighter fit than a target archer would use is often preferred.

Pick the nock kind that fits how you shoot

The "Kind" column sorts nocks into a few groups:

• Standard: a one-piece plastic nock that presses into the shaft
• Pin: a small nock that clips onto an aluminum pin glued into the shaft
• Lighted: a nock with a battery and an LED that lights at the shot

For most hunting arrows, the standard press-fit nock is the default. Easton's tuning guide notes that its Super Nock, a press-in S nock, is made with a tighter fit because of its use as a hunting nock. Pin nocks are mostly about protecting the shaft, for the reason in the pin section below. Lighted nocks get their own section below and their own page.

Count arrows per pack against your quiver

Packs run from a few nocks to a dozen or more, and the table shows the count the listing gives. Lighted nocks usually come in small packs. Standard nocks come in larger ones because you'll replace them more often.

Here's how I count. Take the number of arrows in your quiver, add the arrows you practice with, and plan on a spare for every few of those. Nocks break in tight groups, and they always break the week before the season. That's not physics. That's just November.

Check the "For" field before you check anything else

Arrow nocks and crossbow nocks are not interchangeable. The table marks each product "arrow" or "crossbow bolt." Crossbow nocks are sized for bolts and shaped for a crossbow's rail and string. If you shoot a vertical bow, filter out the crossbow rows first and you'll have half the reading to do.

Types of arrow nocks and when to choose which

Press-fit nocks for most carbon hunting arrows

Press-fit nocks slide into the back of the shaft with no glue. You push until the shaft end meets the nock's shoulder. Because they're held by friction alone, you can turn them to any position. That matters for two things: lining up with your fletching, and getting vane clearance past your arrow rest and the bow's cables.

Turning a press-fit nock is the cheapest tuning adjustment in archery. If one vane keeps ticking the rest, rotate the nock a few degrees and shoot it again. No glue, no tools beyond your fingers. (A quarter turn has fixed more of my fliers than any new part ever did. Uncle Walt watches me do it and says nothing, which is the meanest thing he does.)

Pin nocks protect expensive shafts

A pin nock clips onto a small aluminum pin that's installed in the back of the shaft. The pin acts like a bumper. Archery 360 calls a pin nock an excellent choice for protecting expensive arrows from splitting when another arrow hits them.

The trade: a pin system is more parts at the back of the arrow, and every part is one more thing to check. Pins earn their keep for archers who shoot tight groups into the same spot all day, since tight groups are exactly what Archery 360 says cracks nocks. Most deer hunters don't shoot that tight that often, at least not on purpose.

Bushings and collars sit between the two

There's a middle path. A uni-bushing is a small sleeve glued into the back of the shaft that accepts a standard push-in nock. Easton's tuning guide calls it an internal-fit system and sizes its bushings to the nock: the standard UNI bushing takes G-series nocks, the Super UNI takes Super Nocks. A nock collar wraps the shaft end instead, and Archery 360 mentions an insert nock with a collar as a good option for protecting the shaft.

If you go this route, buy nocks sized for the bushing, not for the bare shaft. Some lighted nocks also ship with plastic adapter sleeves. One maker's universal nock includes sleeves that let one nock body fit .204, .233, .244 and .246 shafts.

Over-nocks and conventional nocks for specific shafts

Over-nocks slide over the outside of the shaft instead of into it. Easton's guide says some carbon shafts require them, and that they go on either dry or with a mild adhesive like rubber cement, not regular fletching cement, whose solvents can attack the nock plastic. Buy the one the shaft maker specifies.

Conventional nocks fit aluminum arrows that have a cone-shaped back end called a swage. Easton's guide sets them with an even layer of fletching cement on the clean taper, then lets them cure at least two hours before shooting. Don't cut an old one off with a knife; scoring the taper makes the next nock sit crooked. If you shoot a traditional bow, check the arrow maker's recommendation first.

Lighted nocks for tracking the shot

A lighted nock has a battery and an LED inside a nock body, and a switch turns it on when the string pushes the arrow. The light shows you the arrow in flight and where it ended up. Lighted nocks weigh more than standard nocks; Bowhunter puts the difference at 8 to 15 grains, depending on the maker. That's enough to tune for.

Battery life, activation types, turning them off, and whether they change your accuracy are all on the lighted nocks page.

Crossbow nocks need the right end

Crossbow nocks come in several end shapes. A flat nock has a flat back. A moon or half-moon nock has a groove the string sits in, and you load the bolt with the groove lined up to the string. One crossbow maker's nock guide names flat, moon and capture nocks as the common shapes, and warns that with the wrong nock the string can shoot over or under the bolt, which acts like a dry fire.

Which one is right isn't your call. It's in your crossbow's manual. One crossbow maker's safety page tells owners to use only bolts with moon or half-moon nocks in its bows, and warns that a dry fire can cause catastrophic damage. Other crossbows require flat or capture nocks. Match the manual, then look at the rest of the specs. Bolts themselves are on the crossbow bolts page.

Installing and aligning new nocks

Swapping a press-fit nock takes about a minute per arrow:

1. Pull the old nock straight out. A nock tool or pliers wrapped in tape helps if it's stubborn.
2. Check the shaft end for cracks or splits. A damaged shaft end gets the arrow retired, not a new nock.
3. Press the new nock in until the shoulder meets the shaft end. It should sit flush and square.
4. Turn the nock so the groove lines up with your fletching the way the rest of your arrows are set.
5. Snap it on the string and do the click test.

Keep every arrow in your quiver on the same nock model. A mixed set means mixed string fit, and mixed fit shows up as fliers. If you change nock models, change them all. That includes the arrows you're "saving for later." (I have four of those. They've been saved since 2019.)

Check your nocks before every session

A cracked nock can break on release and dry-fire your bow, which can damage the bow and hurt you. Replace any nock with a crack, a chip or a loose fit before you shoot it.

Archery 360's inspection guide explains the worst case. A nock may break without letting the string push the arrow out. That can let the string hit your forearm or dry-fire the bow.

How to look:

• Clear nocks: hold them up to a light and look for irregularities in the plastic
• Solid colors: look for thin dark lines, which are fractures
• After a tight group: check the arrow that got hit and the one that did the hitting
• Fit: a nock that clicks on noticeably softer than the rest is worn

Archery 360 also says nocks should be replaced periodically, depending on how often you shoot. If your groups open up and your nocks are old, new ones are a cheap first fix before you start blaming the bow.

Who can skip this page

If you shoot only a crossbow, most of this page is about the other kind of nock. Start with your crossbow's manual and the crossbow bolts page instead. And if your arrows came fletched and nocked, and every nock passes the click test and the light check, you don't need new nocks yet. Buy a spare pack in the right size and put it in the bow case.

The whole job fits on an index card. Shaft ID first. Click test second. Same nock on every arrow. Look at them before you shoot them.