As most of you know, I have been building rods for only about three years. As stated previously, I am graciously and humbly appreciative of the abundance of assistance from many of you within that time frame. Though limited in experience compared to many of you, I feel confident in my ability to produce very good functioning rods which may even be considered pleasing to the eye as well.
Is it simply my lack of experience which makes me wonder why guide rings are sized the way they are? I do not understand why ceramic guides are sized according to the ID of the frame-ring rather than the actual ID of the insert. After all, isn’t that all we are actually concerned with? It seems odd and confusing that the ID of a #6, no-insert guide as a PacBay Minima is larger than a #6 Alonite Fuji which is smaller than the same #6 Fuji guide with a Torsite insert. Is there a logical explanation? Alright, I may be guilty of possibly over-thinking yet again but it is puzzling to me. Without viewing any of your replies, I would opt for a more consistent format where the actual ID of the finished guide for any given size would be identical, with or without an insert, this material or that. An old military saying; KISS = Keep It Simple Stupid is wisely applied whenever possible.
The same applies to 16oz = 1lb, 12in = 1ft, 5280ft = 1mile. Now there is a nice round number! So why aren’t 120 cents = $1.00? I request your veteran, Guru insight, at least concerning the rod related subject in paragraph 2.

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

The first modern ceramic guides were comprised of standard wire frames, already long in production, fitted with ceramic rings. In other words, most ceramic guides weren't designed from the ground up to be ceramic guides. Fuji's were, but most others got caught short and in an effort to get something to market they simply sourced rings to fit their standard wire guides. So, the same wire guides that were sized from inside to inside continued to be sized that way even when a ceramic ring was installed inside them. So a #25 wire guide had and has a larger ID than a #25 ceramic guide. Not saying it makes sense, just explaining how this came to be.
......................

Mark,
In a word, don't lose sleep over it.

Different vendors have the same numbers for guides that may be quite different from one of the other vendors.

When in doubt, just ask the supplier to send you the internal diameter of any guide that you may be considering if you have any questions about it.

This is just one of the reasons that many folks tend to like and to continue to use one specific brand of rod guides. By always using the same brand guide, one gets very familiar with the actual internal ring size of a particular guide along with guide height and any other salient information about the guide or guide set.

However, any time that I have ever had a question about a guide, I have found the answer to be always available on the other end of the phone. I will call my supplier, ask my question and then jot down the answer for any future reference that I might need about a given guide problem or question.

p.s.
I do agree that it would be very nice if a rod guide manufacturer would publish the internal guide size, height and any other information about the guide in their catalogs rather than just using a generic guide size like 20 or 10 or 6.

just one of the things that needs to go to ISO so there isn't so many differences and confusion making the right choice for a proper build .

The best day to be alive is always tomorrow !!
Think out side the box when all else fails !!!
Wi.

The most expensive start-up expense for any particular guide (size) is the mold from which the frame is stamped. Once a mold is made that will properly deep press a ring with an OD of, say, 12mm, the manufacturer has no choice but to create a ring of 12mm OD. Ring material characteristics (fracture resistance, resiliency, strength etc) then dictate the final shape (thickness) of the ring to meet certain requirements. Ring thickness is driven by the type and amount of material needed to perform at certain levels of durability. So, rings can easily match a predetermined OD but the ID will vary according to the ring material. This is the reason all ring sizes are quoted as an OD rather than ID.

Thank you for the informative replies from respected veterans including Mr. Fuji himself. Considering all the information supplied, I took special note of Mr. Wilson’s remark that many builders use the same brand of guides on most of their builds simply because they are familiar with the actual ID of the opening. While I am, for many reasons, a self admitted proponent of anything Fuji in general, guides in particular, I was unaware of being guilty of exactly what Roger described. I suppose I will not venture to far or often from my Fuji comfort zone until the industry standardizes actual guide IDs.

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

Jim Ising Wrote:
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> The most expensive start-up expense for any
> particular guide (size) is the mold from which the
> frame is stamped. Once a mold is made that will
> properly deep press a ring with an OD of, say,
> 12mm, the manufacturer has no choice but to create
> a ring of 12mm OD. Ring material characteristics
> (fracture resistance, resiliency, strength etc)
> then dictate the final shape (thickness) of the
> ring to meet certain requirements. Ring thickness
> is driven by the type and amount of material
> needed to perform at certain levels of durability.
> So, rings can easily match a predetermined OD but
> the ID will vary according to the ring material.
> This is the reason all ring sizes are quoted as an
> OD rather than ID.

Jim. For future reference the guide frames are stamped from a die, not a mold - molds are for making castings. (I used to be a tool & die maker.)

While it's easier for the manufacturer to list a guide insert's OD, your description of why it's done (because the ID varies from material to material) is WHY people want the true ID listed for guides.

Fuji would further establish themselves as the industry leader in rod guides if they would either list the guides by ID or at least make the information readily available on the web.

Thanks.

I won't disagree with the idea that having the ID of the actual ring opening would be helpful for rod builders, but also realize that many manufacturers use a variety of various ring types and materials in the same frame. This means for any given frame, you may have several different "sizes" to list. What might be doable, would be a combination sizing designation - first number for frame size and second for actual ring opening, i.e. for a size 25 frame and a ring that provides an actual inside to inside width of 23mm, 25/23.

........

Not a bad idea Tom...as long as Japan supplies the info, lol. I'll defer to someone more deft with a micrometer who has enough time to measure thousands of guides!

Dan, in our discussions with Fuji they refer to the dies as "molds". Perhaps it's a translation issue or an effort to help us understand better. I suppose I've picked up the habit but you are correct.

Tom hit the nail right on the head with his second post. Fuji alone offers at least 4 different ring materials. Of those at least 4, I know three of them, based on the material the ring is made of, have different IDs for the same size guide. While the combination sizing listing is a fine idea, I also think it would be confusing to more than a few people. So much so, that in this day and age, it may cause people to shy away from using the product. I know I myself would not care to order guides with dual designations.

Instead, I am of the belief that manufactures should make this sort of information readily available to the consumer. You shouldn't have to go through 10 pages of an internet search and still not find the information you're seeking. It should be there on the manufactures web site. I love the guide height comparison chart on the Angler's Resource page. The same could be done for the information concerning ring IDs, and it would be a much smaller chart.