Grant,
I have IM7 blanks that weigh less than IM9s. I'm not really sure what your getting at. There's much more to the weight issue than what IM series it is, even if it is a made up IM series. Obviously if Hexcel only make IM4, 6,7, 8 and 9 fabric, there is no such thing as IM15 or IM20. I just made it up like whoever did with IM10. However, I'm sure over the next few years will see someone start calling their blanks/ rods IM12. Maybe I should trade mark IM12 for use with my own blanks.

It's a little confusing, but here is a link to a summary page showing all the relevant data for each fabric.
Link

Do you make your own blanks? How do these companys that make them get away with the IM10 if there is no such animal? I know you said someone made it up but do you know 100% nobody is making them? I am not being a smart A-s just would like to know why you think this company is the only one that makes these fabrics. The guys I get my blanks from buys about 10,000 at a time from a well know blank market company and that's just one blank there are plenty more he buys and I think he knows the diffrence in IM 4,6,7,8,9 just asking.

Grant,
If the guys that make the IM fabric don't make IM10 fabric, then there is no meaning to IM10 like there is with IM4, 6, 7, 8 and 9. It's a made up name much like my IM15 or IM20. My guess and it is only a guess is that Hexcel had not trade marked "IM10". I realize you can buy IM10 rods and blanks and I expect you'll be able to buy IM12s in the next few years (assuming Hexcel has not trade marked IM12).

I mean no disrespect to you or the guy you buy your blanks from, but if he doesn't know that IM10 is a made up name, he isn't as knowledgeable about actual blank manufacturing as you think and just repeats blank maker marketing and hype.

Let me add that I have no problem with "IM10" rods/ blanks. There are some very nice blanks/ rods labeled IM10. It's just that the label is meaningless unlike when you see IM6,7,8 and 9.

I'll go back to the original question posted in this thread, what's the difference between IM6,7,8,9 and 10. The difference between the IM6-9 fabrics is tinsel strength ranging from about 600-900 ksi and the blanks/ rods will have different scrims, resins and finish. The modulus ratings for the IM6-9s are all pretty close 40-44 million. In threory, the IM9 should be lighter than the IM8 and it lighter than the IM7

The difference between the IM10 and the others could be anything because there is no IM10 fabric. Unlike the others, IM10s could be any modulus or tinsel strength.

Grant, the way that I am understanding this is I is for intermediate and if it goes up to 10 that would be high. Maybe, I am just high and think that I get it I think that this is a great read, even if I don't really understand it all.

Is there such thing as HM ?

By the way, the word is "tensile", not "tinsel"...sorry, just the old English teacher in me...no offense meant.

No offense taken. I'm a terrible speller. I wanted to spell it tensil, but my spell checker always corrected it to tinsel.

Let me try an analogy. IM4,6,7,8 and 9 are a brand name of fabric (think about Chevy 350 small block). The IM10 is not a brand name (think generic small block). You know if you buy a small block at your local Chevy dealer, it will have certain characteristics regardless of what dealer you buy from (much like IM7 rods from BPS or Cabela's being similar). However, the generic small block may or may not have those characteristics. This is not to say the generic block or IM10 for that matter, can't be great, they can. It's just not a Chevy small block with the uniform standards Chevy imposes. Anyone can build a generic small block and sell it, much like anyone can call a blank an IM10 regardless of what characteristics it has.

Another analogy is Goretex. It is a brand a water proofing material. If you want to call something Goretex, you have to buy the material from WH Gore and manufacture your jacket using their approved techniques. You can use other waterproof material to make your jacket, some of it even identical to Goretex because their patent has expired, but it isn't "Goretex" because that is the brand you can only buy from WH Gore. You can also buy cheap waterproof material that may or may not work as well as Goretex and use that for your jacket. With Goretex, you get standards and you can only buy it from WH Gore. Anyone can manufacture the generic fabric and it may or may not be good.

I hope that helps make it clear, IM6,7,8 and 9 are made using a specific intermediate modulus fabric from Hexcel with 40-44 mil modulus and tensile strength of 600-900 ksi. The IM10 could be made using any fabric from any manufacturer.

HM is a generic term for high modulus. Typically anything over 50 million is considered high modulus. You'll sometimes see reference to mid modulus blanks/ rods and those are typically made with a 33 mil modulus fabric.

Wow, My heads going to expolde!

I have been told by more than one rod rep that there really is no industry standard for measuring different types of graphite blanks. I feel like should rely more on the way the rod fits you than try and let a bunch of numbers and hearsay from the marketing department tell you what rods you should be fishing. Just how I feel.

Welcome to the TFF Sir...It only gets Worse/Better

Small Block 400, 350, 305, 327, 302, 283 and even 265.

I'm still confused.........and without my glasses I doubt I can tell a IM8 from a 10.

Well my blanks are IM8 our main seller but I am as confused as the rest? I have bought and used IM10 that they don't make but I am being told other wise like I said not being a smart a-s here just don't know where this came from? But I just can not see this being the only company makeing IM fabric sorry. My blank guy buys and sell blanks all over the country and he is as confused as us when I told him to look at this he said OK we don't have IM10 so why do I buy IM10 blanks b/c some one made it up for marketing hearsay. I really don't know what to ask and only get this is the only company that makes IM I just can't see it sorry for being hard headed but that's how I am or aleast told I am LOL!!!!!

The sad thing is that I only know how to use a rod and not make one, but this conversation is pretty easy to follow.

It is clear that the IM10 is not a product of the Hexcel corporation (the original manufacturer of fabric for rod building) and the IM10 that is being used is from a another company. Not that I care...but someone should be able to look up the specs of the IM10 product and see how those specs compare to materials from Hexcel for IM6, 8 or whatever...

This thread also points out that there are MANY variables to rod building...which is just stating the obvious when we think of how many different rods we have used in our lifetime and how different they all were.

Bout sums it all up!

Good job Fuzzy!

Ok, I called and sent emails to some people I know at a few of the large OEM rod makers to ask for some clarity on this subject.

Quick answer - Most of the big names that call their rods IM6-9 are using Hexcel fabric. One person told me if it's made by a US based manufacturer and it's called IM6-9, it's most likely Hexcel fabric, even if it's made in Asia. The 2 manufacturers where I know someone that have "IM" series blanks confirmed they use Hexcel fabric. They did say however, the cheap rods using the IM6-9 labels are usually not made with Hexcel fabric, but with fabric made overseas that is "the same". No one knew if "IM6" and the rest are trade marked, but they weren't aware of anyone ever being sued. So in theory, you could label any rod IM6...IM9 and this may be happening.

They all said the same thing about IM10, it could be anything. There are some very high quality IM10 rods/ blanks. One of the guys I spoke with works for a company that makes IM10 rods and he would only confirm that they are higher modulus and tensile strength than IM9s. It was also interesting in that he insinuated they are using a Hexcel fabric when I asked him how Hexcel felt about using their naming style. He said they are not using Hexcel "IM10" fabric, but insinuated it was still from Hexcel and that's why the had a good relationship with them and had no trouble using IM10. But, the same guy warned that there are some very crappy rods/ blanks out there labeled IM10

They all also noted that modulus is only a small piece of the puzzle and isn't really good for anything but marketing unless your comparing rods from the same manufacturer and even that could be iffy. One guy told me his sales team was always pushing for higher modulus rods to compete and that's when the stopped listing their modulus. I won't say where this guy worked, but he pointed out that he wasn't aware of any domestic made rod that retailed over $200 and listed the modulus. He named of a bunch of manufacturers, some I'd never even heard of that make high end fly rods, and said to the best of his knowledge, none listed modulus. He said the main reason is that most rod makers of high end rods/ blanks use multi modulus fabrics for their rods/ blanks. The may use a high mod in the lower section and IM in the middle or tip. He said they use as many as 3 different fabrics in one rod.

It was interesting to go through this process. I communicated with 5 people at some of the largest rod/ blank makers based in the US, two of whom I know fairly well and they were all unbelievably secretive, even the two guys I know well. They were free with general information, but very tight with any specifics about their rods. Because the rod/ blank manufacturing business is so incestuous, most knew almost as much about their competitors rods as they did about their own and were freer with this info, but not as much as I'd expect.

So I'm sure that makes everything clear as mud.