# Carbon Arrow Sizing is Confusing



## DaveHawk

Why in the world does every manufacturer of carbon arrows have a different sizing method and chart? I have been shooting aluminum for years, and a 2315 is a 2315 is a 2315 no matter who makes it. Now I am finally considering carbon, but I don't want to be forced into choosing a brand before I select a size and spine. I suppose different carbon shaft manufacturers utilize different methods and different configurations of materials and thats why. Did I just answer my own question there? Maybe I'll just stick with my aluminum as long as I can find them.....Just an old timer venting a little.....:BangHead:


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## why3zx

naw, they all pretty much make the same things just call them by different names, which is nice, like an easton 400 spline is less than a 340 spline, but if you go to carbon express then a 250 is lighter than a 350, and the same with pse arrows, the lower the number the lighter the spline, basically just pick your brand and then get the right spline, pretty much everyone makes what you need for whatever you are shooting. and just think, you can put your arrow straightener in the classifieds. :darkbeer:


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## ebonarcher

I started shooting in 2006. I've hot nothing but carbon arrow. And I found trying to figure out the so called system of aluminum arrow shaft system nothing but confusing when trying to find uni-bushing to fit into carbon arrows. So I feel your pain . But I've seen enough aluminum arrow come in to the local shop for straighting to know I want no part of them.


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## Nitroboy

why3zx said:


> naw, they all pretty much make the same things just call them by different names, which is nice, like an easton 400 spline is less than a 340 spline, but if you go to carbon express then a 250 is lighter than a 350, and the same with pse arrows, the lower the number the lighter the spline, basically just pick your brand and then get the right spline, pretty much everyone makes what you need for whatever you are shooting. and just think, you can put your arrow straightener in the classifieds. :darkbeer:


*It's SPINE not SPLINE people!!!:wink: Sorry I had too!*


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## 3children

The difference is carbon is measured by spine,(backbone) of the shaft. Aluminum is measure by the size ex: 2315 is measured od of 23/64" and the 15 is measured in thousand of an inch=.015 wall thickness. The second two numbers tell you how thick the wall of aluminum you have the first two tell you how thick the arrow is!


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## bfisher

The sizing charts and numbers on carbon arrows does get confusing, just as you are finding out. I assume you have been using 2315's. OK, the first two numbers are the shaft diameter in 64th of an inch. The second two numbers are the wall thickness of the shaft. These two combine to form a certain SPINE deflection, which is usually shown on some of Easton's charts.

When it comes to carbon arrows it's a whole new ball game. Almost very manufacturer has some different method for numbering their arrows. Easton and Beman (same company) are the ones that get it right. Their arrows are marked with the actual spine deflection, or stiffness. The smaller the number
(500,400,340, 300) the stiffer the arrow. The Gold Tip Ultralite series are numbered the same way.

Some companies put different numbers on their arrows that correlate to the spine, but are not the actual spine deflection. PSE and Carbon Express come to mind on this. They are backwards in relation to Easton's method with 400 being stiffer than 200. 

Then their are some, usually cheaper grade arrow arrows, tht are marked 4560 or 6075, or 7595. These are meant to designate at what poundage the arrows can be shot at, but are not always accurate, as it differs with the length of the arrow, point weights used, cam style, and draw length of the bow and so forth.

Here again, each manufacturer provides a chart showing which arrow spine to use at certain poundages and arrow lengths. These are usually just some sort of guideline as to where to start.

What needs to be done here, as with a lot of things in archery, is to come out with some standard by the ATA for arrow manufacturers to spine test their arrows and mark them accordingly. Somehow, I don't see this happening any time soon, but it should be done for the sake of the consumer.

One thing nice about carbon arrows is that they are more adaptable in that a particular shaft can be shot over a wider range of draw weights for a given length with other things taken into consideration such as cam style, etc. Aluminums usually have a less narrow range, but there are more sizes to pick from, but this is changing too, as the demand for them is ebbing in favor of carbon arrows.


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## dmr

why3zx said:


> naw, they all pretty much make the same things just call them by different names, which is nice, like an easton 400 spline is less than a 340 spline, but if you go to carbon express then a 250 is lighter than a 350, and the same with pse arrows, the lower the number the lighter the spline, basically just pick your brand and then get the right spline, pretty much everyone makes what you need for whatever you are shooting. and just think, you can put your arrow straightener in the classifieds. :darkbeer:


I'd hang on to your straightener if I were you. Sold my straightener when I switched to carbons four years ago, but now I'm in the market for a new one. Finally got tired of my Easton Axis (300 spine, original and nano) filling up deer bodies with carbon fiber... so switched back to aluminum (Easton XX78 2317). Decided it's better to straighten a shaft occasionally, than have to worry about ingesting carbon fibers or a broken shaft shot through my arm. Have yet to bend one of these 2317 Super Slams, even when I missed the target and hit a tree trunk - shot from an 80lb Hoyt AM32. Put it on the arrow spinner after chiseling it out of the tree, and it was still straight.


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## Spotshooter2

> It's SPINE not SPLINE people!!! Sorry I had *too! *


 That should be* to*:wink:
Anyway , actually I wish that aluminums put the spine on their arrows also like most of the carbons. Like say a 2216-.400. Now I am not sure if a 2216 is a .400 spine but that would help out a lot trying to figure out which aluminum would work best. And I agree , it would be nice if they ALL did the carbons the same way by just putting the spine number on the arrow.


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## DaveHawk

*Thanks for the Input*

OK, OK guys, I know aluminum shaft designations and sizing. I am a tool and die designer, so I know that a 2315 is 23/32" O.D. with .015" wall thickness. I also understand the principles of arrow spine as they apply to length, poundage, broadhead weight...etc. I have always been extremely happy with my aluminum shafts. They are, after all straighter out of the box than carbon (read the specs). I do have an arrow straightener collecting dust in my arrow building room, and I can't even tell you the last time I had to use it. My shafts are durable to say the very least. I just can't find the selection that I used to. So, I was thinking (briefly) about switching before I am forced to. I think there are some of us who will always prefer aluminum to carbon, and I'm fine with that. Hopefully there is enough demand for aluminum to warrant continued manufacturing. If we all had to use the same equipment, how boring would that be?? Thanks everyone, for all your input, but I'm still confused as to why these carbon manufacturers can't standardize their sizing, that's all I'm trying to say here...:elch:


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## LFM

What gets confusing is when some have a 3 digit system and others have a 4 digit system and some have both. What needs to happen is to have a chart that has the Aluminum Size and what it equals to the carbon arrows like Carbon Express, Gold Tip, Victory, Trophy Ridge, Beman and the others out there. When I made the switch over I just asked the brand I was looking to switch to to get what was close to the 2514 and I was told that the Gold Tip 7595 was close as well as Eastom Axis FMJ's 300's were. I went to a shop told them the arrow I was using prior to asking te manufacturer and they sold me Carbon Express 4560 instead of the right ones 6075. Being a shop I bought the 4560 and wasted the money because you can't take them back once cut or that is what I was told. The arrow with a field point hit at one place and when I switched to BH's it was about 8 inches left and and 5 inches low. Yet with my 2514 the point of impact was the same or very close. So the posters question is valid because just taking one persons information sometimes is a waste of time and money. I would go to the different manufacturers and ask them what arrow is equal to the 2315 and they should give all arrows they make that are equal to that size but in a carbon size. Once you have that then you can decide on what carbon brand you want to buy and try. Or what is available and if they will cut them to length and install the insert if you do your own fletchings. It is a learning curve because most if not all aluminum arrows were made by Easton today their are so many carbon makers and each has their idea of what a good arrow is. They have low, medium and high end arrows. If you are looking to buy the top of the line or what you can afford.

Good Luck,
LFM


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## AHBH

*arrow sizing is confusing*

I must say it is a very confusing topic and I would appreciate it if all the manufacturers will use one standard to identify arrows with or is it financially beneficial to them to keep us confused:sad:


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## trainer_will

2315 aluminum are spined at .340....just so you know.

Will


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## joeve

IMHO carbon arrow manufacturers should give consumers 3 specs. Inside diameter since inserts, nocks, etc. rely on this. Outside diameter since nocks and inserts rely on this also to be flush with the exterior wall of the shaft. Lastly spine which is vital for different poundage and speed. Composition finish etc. they already list as selling points. I'm sure I missed something, but it is tough to match components with the current system. Maybe its intentional.


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## hooyter's

joeve said:


> IMHO carbon arrow manufacturers should give consumers 3 specs. Inside diameter since inserts, nocks, etc. rely on this. Outside diameter since nocks and inserts rely on this also to be flush with the exterior wall of the shaft. Lastly spine which is vital for different poundage and speed. Composition finish etc. they already list as selling points. I'm sure I missed something, but it is tough to match components with the current system. Maybe its intentional.


AGREE!! after i figured out all of the different mfg's sizing numbers i started looking at OD-ID components sizing etc..needless to say it was a headache trying to decide which to buy and stick with


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## mitchell

For me the easiest way to get this in my head was to learn "deflection". Deflection is a measure of spine. It measures how much the shaft bends when suspended between two points 28" apart. Most carbon mfgr give you the deflection of their various models. 

By the way, I agree totally that there is way much room for improvement in how this is done for the sake of the consumer.

Once you get an arrow matched to your bow, you can then find our what deflection it is and use that for shopping with other brands. For example, at my draw weight, on my Hoyt fingers bow set at 54# and 28" DL, I can cut a Gold Tip 3555 back to 27.5" and it will bare shaft for me. Since I know that a 3555 has a deflection of .500, that tells me that I can shop other brands, look for their particular models that have a deflection of .500, and know that if they are cut to the same length, same head etc they will fly just like the GT 3555.

One step further is to use one of the software programs. Once you get a shaft matched well, you can set your bow and arrow combo up in the system. Then you can go into the system and say, OK, what if I increase my draw weight by 4#? What changes will I need to make to my shaft. The programs will tell you how much length to cut off, or head weight to take off, and will tell you the dynamic spine of your set up in deflection. That also can be helpful in shopping other brands. If I remember correctly, the software will give you other brands in comparable dynamic spine classes.

I am far from an expert, but that has helped me.


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## Ozzibow

mitchell said:


> For me the easiest way to get this in my head was to learn "deflection". Deflection is a measure of spine. It measures how much the shaft bends when suspended between two points 28" apart. Most carbon mfgr give you the deflection of their various models.


This is only half the truth. It's even more confusing....
There are different ways to measure the deflection currently on the market:
1. Distance between the two supporting points 28", deflecting load 2lbs (alpine, for example).
2. Distance between the two supporting points 28", deflecting load 1.94lbs (Easton, for example).
3. Distance between the two supporting points 26", deflecting load 2lbs (AMO, for example)

So make an educated guess.


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## DaveHawk

So what spine is a Carbon Express 350? Is it different for a "Red-Zone" as opposed to a "Mayhem"? Wow Carbon Express has the most confusing spine selection process I've ever seen. Just another reason to buy American made arrows !!:usa2:


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