# Easton carbon arrow diameters, am I missing something??



## warden415 (Dec 15, 2009)

I was looking at Easton's website and carbon arrow diameters. I see they have them broken down as G =5mm
X=5.5mm
H=6mm
S=6.5mm
I will just ask about the Axis and FMJ. But none of the diameters work out how I am figuring them?
The axis, FMJ are listed as X
I know they are 17/64
So if I take 17 divided by 64 I get .265625. If I convert that to MM I come up with 6.75mm? Not 5.5mm
I was doing this calculation because I have some old Cabelas SST 220 shafts that are very small diameter. I believe they are 12/64-13/64
I wanted to see what they were in mm
I figure Easton has it right and I am missing something but every one of the calculations I do, G,X,H,and S
Don't equate either???


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## paul l. (Nov 17, 2008)

Are you sure you aren't getting the outside diameter (17/64) confused with the inside diameter? Just a thought. Good luck.


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## GregBS (Oct 30, 2010)

Different spine rating have different outside diameters. This is why they list different FP sizes. The only constant size is the inside diameter. Measurements are in inches.

Beman (Easton) ICS Hunters (S):

ID = ~.245
500 = ~.284 OD
400 = ~.294 OD
340 = ~.298 OD
300 = ~.300 OD

Easton Bloodline (H):

ID = ~.234
480 = ~.290 OD
400 = ~.292 OD
330 = ~.294 OD

Easton Axis (X):

ID = ~.204
500 = ~.261 OD
400 = ~.264 OD
340 = ~.267 OD
300 = ~.275 OD

Easton Injexion (G):

ID = ~.165
480 = ~.223 OD
400 = ~.230 OD
330 = ~.236 OD

Easton Axis FMJ (X):

ID = .204
500 = ~.258 OD
400 = ~.264 OD
340 = ~.267 OD
300 = ~.275 OD


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## warden415 (Dec 15, 2009)

GregBS, thanks for the info! That does answer some questions. But still, Easton I thought labeled the arrow sizes with X,H,G etc indicating OD? They speak of less wind resistance, planing , better penetration etc, and that would be a function of OD. That shouldn't have anything to do with ID?
So it still seems to me that the 6.5mm, 6.0mm,5.5mm OD numbers are not accurate and are just arbitrary?


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## wrkdvr (Dec 12, 2012)

I have the Easton Bloodlines and was looking at changing to Axis. The Axis is noticeably smaller OD, but the Axis Realtree has a wrap and adds to the OD. I really can't tell a difference in diameter from the Bloodline and Axis Realtree.


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## GregBS (Oct 30, 2010)

The ratings S,H,X, and G are general ratings of diameters. So yes, they are pretty much arbitrary. Unfortunately, if you really look at them, there isn't much difference in the H from the S except components are more expensive. There is really no real difference until you get to the X and G diameters.

Axis Realtree camo only adds ~.002" to the diameter. I'd have a hard time telling my Beman MFX 300s from my ICS Hunter 300s if it weren't for the labels. They are less than 1/32" smaller.


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## Buck_ (Oct 29, 2015)

Hold the reins y'all, I can answer everybody's question.

I've been through this myself. This is what I found with every Easto. Shaft I own. Ill use my carbon injexions as an example. They are G series 5mm shafts. If you physically measure the inside diameter of the shaft, it's 4mm. If you physically measure the outside diameter of the shaft, it's 6mm. Anybody else have that light bulb click lol?

If you add the 6mm OD to the 4mm ID, and divide by 2 in order to get the average diameter, it comes out to 5 millimeters. Advertised shaft diameter is the average between OD and ID. 

Also, not sure about the gentleman that had mentioned something on the lines of the inside diameter remaining constant but increasing shaft spine increases the outside diameter... 

The bow and arrow use basic physics to operate... density and mass do not have to have a positive correlation, they're two completely different traits. As a matter of fact there can be no correlation between density and mass whatsoever. Sure, they do have to pack more material within that given inch on the shaft, thus increasing the density of the overall shaft and reducing pliability, but that doesn't mean the shaft has to become bigger in any way, it just means they have to use more pressure in their machinery. 

So to answer everybody's question, advertised shaft diameter is the average between the inside diameter and outside diameter of the shaft. Additionally, all different spine variables of the same type of shaft from a manufacturer will have the same mass and volumetric measurements, in other words, they'll all be the same size. All they do is use more pressure within the machinery to pack more material within that given inch, noted as more gpi, resulting in a stiffer shaft and reducing the pliability of the shaft, thus we have spine.

It's all about making sure your arrow has the appropriate physical traits so that it allows it to absorb the maxximum amount of kinetic energy that your bow is capable of making available to the shaft. If you're rocking a high powered bow getting out X amount of kinetic energy and you are shooting the wrong arrow, it doesn't matter how powerful your bow is or what it's capable of producing, your arrow is not going to absorb that kinetic energy to its maximum potential and the remainder of that kinetic energy is going to be released elsewhere, such as vibration, noise, shock, etc. This is the very reason safety protocol used to be dictated by AMO before we used IBO. AMO calculations used a 540 grain arrow, which converted to 9 grains per 1 lb draw weight, AT THE VERY MINIMUM. This was because technology did not exist to create a shaft less dense than this that was actually safe to shoot. As technological advances increased, we discovered the technology to drop that 9 grains per 1 pound draw weight all the way down to 5 grains per 1 pound draw, while being used in the 30 grain Arrow which is IBO standard, comes out to 350 grains. Lastly, this is the very same reason archery experts are fighting tooth and nail over whether or not 400 feet per second is even possible. Hell, to 370fps IBO velocity of the PSE Full Throttle damn near violates the laws of physics.


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## JPR79 (May 18, 2010)

Buck_ said:


> Also, not sure about the gentleman that had mentioned something on the lines of the inside diameter remaining constant but increasing shaft spine increases the outside diameter...


While I agree with you on the physics and how the arrow spines go into question, the above is correct, Easton arrow series maintain the same inner diameter. Do you think they make different size arrow components for every single different size spine they sell? No, they make S, H, X, and G components, all to fit the same inner diameters of those arrows.


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## Flatwoodshunter (Feb 3, 2013)

Fractions to Decimals and Millimeters..... http://www.hamuniverse.com/antfrac.html


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## Left I Dominant (Feb 2, 2016)

I think theyre talking nock diameter i with those figures from the original post


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## nvcnvc (Jan 27, 2009)

Buck_ said:


> Hold the reins y'all, I can answer everybody's question.
> 
> I've been through this myself. This is what I found with every Easto. Shaft I own. Ill use my carbon injexions as an example. They are G series 5mm shafts. If you physically measure the inside diameter of the shaft, it's 4mm. If you physically measure the outside diameter of the shaft, it's 6mm. Anybody else have that light bulb click lol?
> 
> ...


Do you realize that the second sentence contradicts the first sentence in the bold part above??? Here's how it works...when the mass increases within a constant volume the density increases. Conversely, when the mass decreases the density will also decrease (volume still constant). This is what you call a direct relationship between destiny and mass. When the mass remains constant and the volume increases, the density decreases. Of course if you squeeze the same mass into a smaller volume, the density will increase. This what you call an indirect relationship between density and volume. In the end you can write a mathematical relationship between the three quantities as Density = Mass/Volume. Please don't spread misinformation if you are not sure about what you are talking about.


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