Frequently Asked Questions
Arrow Types & Constructions
Easton ST (Slim Technology) small-diameter arrows are a patented Easton technology. ST enhances the penetrating performance of arrows. Laboratory testing shows that when kinetic energy is held constant, arrow diameter is the determining factor in arrow penetration. With this understanding, Easton engineered ST as the next big advancement in hunting arrows. ST small-diameter arrows provide significant increases in penetration and less wind drift than conventional-diameter carbon arrows, due to its innovative micro-diameter and reduced surface area. The thicker shaft wall design was needed to deliver the correct bowhunting spine sizes, but more importantly, thick-wall design provides increased durability and enhanced kinetic energy for better downrange penetrating power. ST was first introduced on the AXIS arrow, and has since spread into other all-carbon and A/C Easton shafts.
The choice between aluminum, carbon or A/C products depends on the experience and shooting style of the archer. While there are some true advantages and disadvantages of each design, ultimately this decision is personal preference.
Aluminum arrows have the highest precision-to-price ratio of any arrow construction. The nature of aluminum allows for extremely precise manufacturing specifications, especially concerning weight and spine, which are the two biggest determinants in arrow accuracy. Aluminum arrows also tend to fly better and tune easier when using fixed-blade broadheads, and because they are heavier and transfer the bow's energy more efficiently at the shot, aluminum arrows are deadly quiet out of hunting bows.
Carbon arrows are generally lighter in weight, which means high velocity and flatter trajectory. This added speed helps overcome errors in range estimation. However carbon is not as precise as aluminum, which inherently means less accuracy. Carbon is also lighter weight, and reduces velocity more quickly, which means less penetration and kinetic energy downrange.
Alloy/Carbon arrows provide the best of both worlds, delivering the strength and durability of a carbon arrow, and the spine consistency, weight tolerances, and accuracy of an aluminum arrow. Because of the enhanced and difficult manufacturing process, A/C arrows tend to be priced higher than all-aluminum or all-carbon counterparts. However, when considering the overall benefits and that the only downside is slightly higher price, A/C arrows are a fantastic buy and the top choice of many pro-level shooters and bowhunters.
Full Metal Jacket technology is a new, patent-pending exclusive arrow construction only from Easton. This inside-out A/C arrow combines the best attributes of carbon and aluminum with a new twist. The small diameter and thick wall carbon-fiber core with Hidden Insert Technology (HIT) provides superior penetration, durability and accuracy. The aerospace alloy aluminum jacket provides more consistent spine, straightness, and weight than all-carbon arrows. The end result is an arrow with outstanding accuracy, durability and bone-crushing penetration. In addition, FMJ's innovative metal jacket design delivers easy arrow removal from tough, high-density 3D targets, when compared to all-carbon arrows.
Correct arrow length is measured from the bottom, inside of the nock groove (deepest point where the string goes into the nock) to the cut end of the shaft. See Easton Tuning Guide, page 15 for illustration. Visit the downloads section for free download of the Easton Tuning Guide.
Each and every shaft that Easton produces has its own components specifically designed for that particular shaft. Selecting the correct components will be important when trying to replace damaged or misplaced components. Refer to the Easton Arrow Guides or the Easton website for complete component specifications for your particular shaft.
The HP insert is patent-pending technology designed by Easton to provide greater point precision and accuracy than standard RPS inserts. The extended design provides more contact with the arrow shaft for improved point-to-shaft alignment. The end result is more accurate broadhead alignment to the shaft, which results in better arrow flight. For 2007, the HP insert system is available as standard equipment only on the redesigned Easton ST Epic arrow.
Easton does not produce a G-nock UNI-bushing for the Fatboy shaft. All Fatboy shafts come standard with the standard Super UNI-bushing that will accept the Super nock or the 3D Super nock. These Super UNI-bushings come factory installed directly from Easton.
The HIT insert will only install into the Axis model-line and the A/C Super Slim. These models include: ST Axis Full Metal Jacket, ST Axis, ST Axis Junior, ST Axis Realtree APG, ST Axis Mossy Oak Obsession. For the Beman shafts, HIT insert will fit MFX Team Realtree and the Classic MFX shafts. The HIT insert comes factory direct with all of these shafts ready to install.
HIT was originally designed to fit next generation, small-diameter (ST or Slim Tech) arrows that are built for more penetration and better durability. Due to the new, small-circumference design, standard, lipped inserts would no longer be compatible. HIT was engineered to fit up inside the arrow shaft, hidden from view. HIT gives automatic broadhead alignment because the broadhead shank aligns directly against the shaft wall for easy, no-fuss broadhead setup. Perfectly aligned broadheads mean more accuracy and tighter broadhead groups. HIT and ST Slim Tech) combine to form the next great advancement in hunting arrows, and more accuracy, durability & penetration than standard carbon arrows.
Although the HP insert is engineered for the ST Epic and ST Epic Realtree arrows, the HP insert is compatible with the new ST Carbon Excel arrow. HP inserts can be purchased at any authorized Easton dealer, or from Easton's online pro shop.
Arrow Spine & Weight
There are two different types of spine - STATIC spine and DYNAMIC spine.
STATIC spine is measured by the amount of flex in the arrow when an 880-gram (1.94 lbs.) weight is suspended from the center of the arrow. The arrow must be 29" in length and supported by two points, which are 28" apart. The number of inches the arrow deflects or bends due to the weight, is the spine size or measurement of an arrow.
DYNAMIC spine describes the way an arrow reacts from the stored energy of a bow as it is shot. Several factors determine the way an arrow is going to react when shot out of the bow, including method of release (fingers or mechanical release), amount of energy applied by the bow, the bow's cam system (single, round wheel, hard or soft), weight of the arrow, spine of the arrow, length of the arrow, point weight, nock weight and fletching weight. Even nock set material (traditional brass nock or serving nock), along with string and serving material can influence dynamic spine. Because of the nearly unlimited variables in determining dynamic spine, arrows are usually measured using static spine.
The four-digit number refers to the outside diameter and wall thickness of the shaft. The first two numbers are the outside diameter in 64ths of an inch. The second two numbers are the wall thickness in thousands of an inch. For example, a 2514 shaft would be 25/64th of an inch in diameter and .014 of an inch wall thickness. OD and wall thickness are the two variables in controlling spine for aluminum arrows.
Spine is very important when it comes to tuning, shooting and grouping your arrows. If you do not have the correct arrow spine for your bow set up, you are going to get erratic arrow flight and poor shooting groups. Having the proper arrow spine is key to optimizing the grouping of your arrows and for the best possible accuracy. Use the Easton Shaft Selector or reference the Shaft Selection Chart in the back of the Easton Arrow Guide to make sure you are shooting the correct arrow spine for your set-up.
The industry standard measurement for weight is grains per inch (GPI). There are many factors that make up GPI including: arrow diameter, wall thickness, and shaft material. The GPI weight of listed arrows does not include the weight of the point, nock, insert or fletchings.
Fletching & Assembly
Although Easton arrows go through a rinse stage in the manufacturing process, it is always a good idea to give your arrow a quick cleaning. After cutting your arrows to length, use a Q-tip with a little acetone or 91% isopropyl alcohol to clean the inside of the arrow where the insert or bushing is being installed. This will allow better adhesion for your fletchings and other arrow components. For complete and detailed directions on arrow set up, reference the Easton Tuning Guide, or download free here.
Carefully wipe down just the fletching area of the shaft with M.E.K. or acetone using a clean, white paper towel. If your nock is already permanently installed, use 91% isopropyl alcohol in place of all other solvents. Continue wiping the surface with solvent until no dirt or carbon residue shows on a clean portion of the paper towel. Remember to use protective gloves to keep solvents off the skin and use proper ventilation. Do not soak carbon or aluminum/carbon shafts in any solvents. CAUTION: Do not use lacquer thinner, M.E.K., or acetone with the nock installed. Keep these solvents away from nocks and shaft identification markings. Petroleum solvents could accumulate between the bushing and shaft wall and weaken the adhesive bond. For complete and detailed directions on arrow set up, reference the Easton Tuning Guide, or download free here.
Although there are many different types of fletching glue on the market today, Easton recommends that you use Easton Quick Bond adhesive for best results when fletching Easton products.
Because of the pre-applied activator on Easton Diamond Vanes, no cleaning is required if AAE Fastset™ adhesive is used. If another brand of adhesive is used, or for other brands of vanes, wipe the base of the vanes with MEK or lacquer thinner to remove any mold release chemical from the vanes.
While there is some personal preference involved, Easton has found optimal performance by placing all factory-fletched arrows 1" from the nock-end of the shaft to the start of the vane.
CAUTION: Do not soak any carbon shaft in solvents to remove the fletching or fletching adhesive. This can weaken the resin that bonds the carbon fibers.
1. When using instant adhesives, carefully peel off the vanes with a knife (not razor sharp) and remove most of the glue, being careful not to scrape deep enough to damage the carbon fibers along the shaft's surface.
2. If using standard fletching cements, pull the vanes or feathers off by hand or with pliers.
3. Wipe fletching area with lacquer thinner to remove any remaining glue residue. Do a final wipe with 91% isopropyl alcohol.
CAUTION: Keep solvents away from the nock and shaft logo.
4. Let shafts dry thoroughly before re-fletching.
For complete and detailed directions on arrow set up, reference the Easton Tuning Guide, or download free .
Easton only recommends Easton hot melt for installing inserts into aluminum shafts. Super glue or quick-bonding glue will become brittle over time and could cause inserts to loosen or fallout.
Easton does not recommend any type of hot melt glue for any carbon arrows. Heat will damage the structure of carbon shafts and should always be avoided.
Easton Broadhead Adapter Rings were developed for carbon shafts to provide a larger mounting surface when using broadheads with O-ring and other compression-based blade retention systems. The larger mounting surface allows O-rings to compress rather than roll over the top of small-diameter inserts. In addition, the adapter ring provides a smooth, tapered fit from the broadhead ferrule to the insert. Each Easton shaft has a specific size of a B.A.R that needs to be used with that particular model and spine size. Locate your specific arrow model and spine size to determine the correct B.A.R. for your set up.
Easton recommends using the broadhead adapter ring (BAR) if required by the broadhead manufacturer. Broadhead Adapter Rings are required for fixed broadheads that utilize the face of the insert to support or hold the blades in place. Broadhead Adapter Rings are required for mechanical broadheads that use the insert as a stop for the blades after the broadhead has opened.
Medium to heavy weight arrows are better for hunting for a number of reasons. First and foremost, a heavier arrow will retain more kinetic energy downrange, which means greater penetration and knockdown power. A heavier arrow is also more efficient in transferring a greater percentage of the bow's energy at the shot. This means a more efficient use of the actual pounds of force you are pulling back, and less vibration in the form of unused energy, which means less noise and recoil. Imagine the analogy of throwing and/or getting hit by a baseball versus a wiffle ball. A baseball will be easier on your arm when you throw it, meaning it is a more efficient use of your arm's energy. And even though the wiffle ball will start at a higher velocity right out of your arm, the baseball will maintain its kinetic energy long after the wiffle ball has hit the ground. And it goes without stating that the downrange punch will be considerably better with the baseball than the lighter wiffle ball.
Using an archery example-a 350-grain arrow will be faster out of the bow than a 450-grain arrow, but the 350-grain arrow will lose about 12% of its kinetic energy at 40 yards, were the 450-grain arrow will only lose about 4% to 6% of it energy at the same distance.
Kinetic energy of an arrow is the energy it has due to its motion. The more kinetic energy an arrow has, the better the penetration will be when holding other variables constant. To determine the kinetic energy of your hunting set up, or to see how changing factors influences kinetic energy, use Easton's Shaft Selector.
If your bow set up does not have adequate kinetic energy, poor penetration will be a direct result. Getting enough kinetic energy from your current set up is critical when shooting any type of game. Kinetic energy dissipates the further an arrow gets from your bow, making KE even more important when hunting at ranges past 20 yards. To determine the kinetic energy of your hunting set up, or to see how changing factors influences kinetic energy, use Easton's Shaft Selector.
To determine the kinetic energy of your hunting set up, or to see how changing factors influences kinetic energy, use Easton's Shaft Selector
The term F.O.C. stands for "front-of-center." FOC describes the percentage of the arrow's total weight that is located in the front half of the arrow. The more weight that is located in the front half of the arrow, the more forward is the arrow's center-of-balance. An arrow's F.O.C. is critical to optimal accuracy, especially at long-range distances. Easton recommends 10-15% FOC for hunting set ups. To determine FOC for your current set up, see FAQ "How do I determine FOC?"
AMO-Standard F.O.C. balance formula
F.O.C. % = 100 x (A-L/2)
L= Correct Arrow Length-Distance from bottom of nock groove to end of shaft
A=Distance from bottom of nock groove to finished arrow balance position (includes weight of point [+ insert], nock system and fletching)
F.O.C can also be calculated by using Easton's Shaft Selector.
The X-10 and the ACE shafts have a max that you may cut off the front of the arrow. Due to the barrel design of the shaft, you are only able to cut a certain amount from the shaft. Each individual spine size is different in the amount that you may cut. Exceeding the max cut amount will expose carbon and this could lead to damaging the arrow. Go to the target arrow guide, or here to find your model and spine size to determine how much you may cut from the front of the shaft.
The all-new X-10 ProTour arrow is engineered and designed for todays compound bows. Easton has taken X-10 design and technology and improved the performance specifically for compound archers. A unique tapered design and ultra-high modulus carbon strengthens the nock-end of the shaft creating a stiffer tail-spine. The result is stiffness where it's needed and a low profile for ultimate accuracy at long-range outdoor distances. Lighter and even smaller in diameter than the X10, the ultra-thin, aerodynamic X10 ProTour sets the new bench mark for premier outdoor compound arrows.
- Decrease peak bow weight
- Decrease point weight or the point\insert combination
- Use heavier bow string material or add more strands to the string
- Heavier vanes
- Use heavier serving material and\or nocking point
- Decrease brace height on recurve bows
- Shorten the length of the arrow
- Increase peak bow weight
- Increase point weight or the point\insert combination
- Lighter string material reduce number of strands in the string
- Lighter serving material or lighter nocking point
- Lighter vanes
- Increase arrow length
- Increase brace height on recurve