I understand that rods are rated by the content of graphite carbon in the blank.But some rods say something like 57 million modulus,some will say IM-7,8,9 and yet others say 30 ton graphite construction.Can someone explain these different ratings to me.Why is there not a standard for rod ratings
I'm going to try to keep this real unscientific, because I'm not scientific!!!
IM was a term invented by Hexcel, the largest producer of carbon fibers in the US. It was how they named their different fibers. They still use the terms.
Here's some basic info with a great chart showing strength vs. modulus ratings:
http://www.hexcel.com/Products...nuous
Here is another good source for data: http://www.matweb.com/search/M....aspx
The problem comes in that the marketing gurus got ahold of this and knocked what it meant all out of whack. This is where you get IM, ton, million, etc - they all have their own way to describe their fibers. Look at bass pro... they have an IM8, which they say on one rod is 44 mil and on another it's 48 mil... how?
"Modulus number" represents the stress vs strain property of the material (Young's Modulus for the engineers out there).
Material modulus also does not have any relation with the type of resin systems used. Without the resin, the carbon fibers would simply fall apart. Resin makes a huge impact on the performance of a rod and is not talked about by the manufacturers. That, along with design, is the "big secret".
The idea behind using higher modulus material is the tensile strength increases - as tensile strength increases you can use less material to have the same power rod - thereby creating a lighter rod - the lighter rod is then more efficient - and the lighter rod should then be more sensitive. BUT this is also why the higher power rods are "less durable" - there is just less material there to absorb impacts, etc that the rods were not designed to take - so they break easier.
Hope it helps.
So what would 30 ton mean? would that be like IM7
Well ABU Garcia says that there 24 ton rod is a IM 6
And All Star's IM6 is 30+ ton...
http://www.allstarrods.com/sub_whatisgraphite.html
If you look at the Hexcel site, IM6 is 40...
If you are not using the Hexcel fibers and their specific designations, it's marketing... everyone can call it whatever they want and the client doesn't know any different.
Question - what does the material being "30 ton" mean to you?
Rod Buying 101: pick it up. if it feels good - use it.
you can apply this logic to other aspects of life as well, but please exercise discretion.
That would be exactly what rod manufactures hope you will do.Nothing wrong with educating yourself as to what your spending your money for.Thanks for the help guys. I now have a better understanding of what rods ratings are.I had always thought that the higher the IM number the better the rod,Now I know that that is not necessarily true... Good Fishing
Absolutely right on. Rod design is a very dynamic process and the material used is just one of many variables.. in the end it boils down to buying a rod of blank that you like and suits your application..
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