Years ago, decades I guess, I learned to turn my own bugs at the same time as I learned to toss them. The two skills went hand in hand for me. And tying my own flies did save money. Don’t let anyone tell you that it doesn’t. If you keep the patterns to a minimum, and you fish a lot, you’ll break even very quickly.
But as I bought my first half-dozen boxes of hooks, I encountered the confusing, confounding and ridiculous world of fly tying hooks. There were just a few brands available at the time, and the fly shop guys explained right away that there was no set standard for sizing. So a #10 Mustad was a little shorter than the TMC equivalent. Likewise, this was the expectation for wire diameters, gap length and more — no consistency between brands. Furthermore, there was no list available with the actual measurements for each hook and each manufacturer. Instead, every hook builder used the X system.
So I learned what 1X strong and 3X long meant. But would a 2X gap be the same between brands? Nope. That was expecting too much, I suppose.
I remember feeling buried by all the nomenclature for a while. And I took the advice of my fly shop friend behind the counter to stick with one brand — the numbers would start to become familiar, he said. That was good advice, and the model numbers surely did become familiar, but they never made sense. What the hell is a 3906B anyway? Well, it’s a 3X strong wet hook that is also 1X longer than the standard 3906— with a sproat bend. And yes, that’s kind of a silly choice for a call number. I’m sure it made sense to some Mustad engineer, but to the world of fly tyers — the target audience for these hooks, it only served to confuse.
TMC100. Now that made a little more sense. And maybe that’s why I was attracted to those hooks for my dry flies. They were a little pricier but were damn strong for a lighter wire. And they were the first chemically sharpened hooks that I’d bought. There was a difference.
When the internet changed everything, the availability of other hook brands stared all of us in the face. I bought Daiichi, Gamakatsu, DaiRiki (I miss those), Umpqua, and a multitude of off-brands or cheaper alternatives that claimed to be just as good as the expensive hooks. None of them ever were, and none of them ever are. But I’ve learned the hard way, every time. You will pay for cheap hooks, eventually. The inferior metal will bend on a good fish or it will shear off and break under the strain of the best fish in your lifetime. As that swimming tank rounds the corner in the current and you lower your rod tip . . . snap. Goodbye trout. Damn you, cheap hooks.
Amusingly, most of the lousy hook brands seem to take on the random number generator approach to most of their offerings too. Maybe there’s some logic in there for model number choices, but most of us don’t see it. If there is a reason for the numbers, how about sharing that information, so we can all make the connection? Actually, that brings me to my most pressing point . . .
Years ago, we all gave up on any idea that there might be an industry standard developed for what a #10 hook is. That’s not coming. I have hoards of hook boxes laying around because I bought the wrong size. Or more specifically, I bought the same size as the other brand, but tried a different model in a second brand. Wrong size. Do you know how frustrating that is? Yes, you probably do.
So, if there will be no industry standard on sizing and strength for hooks (and there won’t be), can we at least have the dimensions for each hook that we’re sold? Give us the measurements: hook length, wire diameter, gap width. Why is this so hard?
Given the proliferation of hook brands — many of high quality — this seems the only logical thing to do. Give your buyer the information. Tell them what they are buying. This is the information age, friends! Yes, we can handle this!

Thousands of hooks there. And these are the good ones.
I brought this up with a friend yesterday who cynically reasoned that companies don’t give out those stats because they don’t want to be held to a standard on what wire diameter, for example, their 1X nymph hook is. Sadly, I think he might be onto something. I’ve bought hook packs that were clearly different measurements than the previous pack that I’d bought a year earlier, and these were from reputable companies.
I understand more why the cheaper companies and the knock off brands won’t provide the measurements. Because they don’t manufacture their own hooks. They source their hooks from sometimes multiple manufacturers, so quality and consistency is not a hallmark. But longtime, leading companies can certainly build hooks to persistent specs. So why not list those?
Surely I’m not the only fly tyer who wants to see this. Right? Or am I so far down in the weeds here, that I don’t realize that no one else really cares about hook dimensions?
I looked around. I talked to fly shop managers. I emailed companies, and I received similar replies:
— We don’t make that information available to the public.
— The hook specifications that you are requesting are not listed for the consumer.
— Those dimensions are a company secret.
I disagree with this. A lot.
Hook dimensions are not proprietary information. It’s not a secret sauce or recipe that we’re asking for. It’s the mere dimensions of what we are being offered to buy. We are not asking for the specifics to the metal alloy or the tempering process. It’s the size of the damn things.
These dimensions are, of course, measurable for anyone who has the hooks in hand. So how much of a secret can this be?
I believe that since there is no industry agreed upon standard for what the measurements of each hook size should be, then every company should provide information about what they are selling.
In my search, I came across just one manufacturer that lists the specifications for each hook.
Thank you, Ahrex.
For this alone, I’m buying and tying on more Ahrex hooks. If there’s another manufacturer out there that I missed, who actually lists their products with measurements like this, please let me know. And I’ll support them too.

From the Ahrex website.
I think we can have nice things. We can handle good information. So give us the hook dimensions!
Fish hard, friends.
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Enjoy the day.
Domenick Swentosky
T R O U T B I T T E N
domenick@troutbitten.com
Yeah having the measurements would be awesome. I’m sure people would disagree over stuff like where the shank actually ends and I have now idea how you would measure the shank length on a grub hook … hmmmm
What if every fly hook manufacturer/seller simply had web pages that pictured all of their hooks at actual size. That would provide dimensions but an industry standard for strength would still be needed. Never gonna happen so the best advice remains to stick with the same few brands and accept the occasional disappointment as part of the adventure.
I’m tired of the adventure, Rick.
Me too. Lost a big one this season on a weak cheap bent hook that had me fuming. As soon as I got home I threw out about six packs of those weak, cheap hooks. I just don’t see the industry changing for a small handful of disgruntled guys like us.
Maybe an open source website ( like Yelp) for fly hook junkies. Ha!
Another problem is that different manufacturers have their own hook numbering system and the number of one manufacturer does not correspond at all to the number of another manufacturer.
At one time in Russia (USSR) there was a system of numbering hooks according to the width of the throat in millimeters. It was very easy and convenient.
Based on the sizes of hooks from different manufacturers, I have developed my own hook numbering system, close to the European system, but I accept each size in millimeters. When buying, I visually estimate the size of the hook, and later at home I measure it and assign it my own number.
Yup
Great post, Dom. If your view becomes more mainstream than smart companies will oblige. That’s how it works.
Just witness the growth of tight line related gear options- people asked and companies saw there was a market.
I just wonder how many tiers are as fanatical
Hi Mac.
Agreed. But I don’t think that wanting to know the dimensions is fanatical, necessarily. I think we’ve just been trained to think that way.
Dom
I finally started using a metric ruler to measure fly bodies on different hooks, though there seems to be some slight disagreement about that too. Here’s what I came up with:
hk=mm fly body length:
8= 12
10=11
12= 9
14= 8
16= 7
18= 6
20= 5
Neat
I share your frustration with hook sizing as we know it and like you would really like to see the dimensions rather than the current designations.
Thanks For Rattling The Cage,
Jim
Cheers.
You’ve articulated a frustration that I’ve felt for some time now. On a practical note, could you tell me which model of Ahrex hook you use to tie standard nymphs (i.e., Hare’s Ears, etc.)?
Hi Alex. So far, I’ve only used Ahrex streamer hooks — Trout Predator. But I will look into buying and fishing others. Email me if you have success with certain models, please.
Dom
I will.
Agreed. Gaps might be a problem on curved shanks, but that could be solved by taking the measurement at a right angle to the point and the problem of the overall length would take care of itself by extrapolation. Then you have to decide whether to include the eye in the shank length. (I admit that this isn’t a big problem for me when it comes to imitating specific insects, as over the years I have acquired a large assortment of hooks and I can usually find one that will match the {measured} dimensions. My minor gripe is finding modern equivalents for obsolete or idiosyncratic national systems to recreate old or unusual patterns. This is obviously a personal problem….)
Great points, JJ.
Dom
Amen to that! I was part of the “stick with the brand” crowd, until the time came that I couldn’t get my old standbys.. and down the rabbit hole I went. And at this point, after wasting money on all kinds of hooks and rearranging everything in my hook boxes 47 times, it makes no good sense why in the world the makers wont tell us literally how big a hook is! At least they let us know how big the bead is that goes on it. To the millimeter… Guess I’ll just have to learn to live like a rabbit…
Same problem here.
Dom
Somewhat more consistency among bead manufacturers. There indeed should be some communication and greater compatibility on both ends. Good read!
Thank you.
This would suggest that fly pattern recipes should give recommended hook specifications as well. This would be especially helpful if you don’t happen to have the same brand and number hook on hand when tying from a recipe.
I understand your point. And, in fact, among my circle of friends, we talk about streamer sizes in inches. I don’t care what size hook it’s on, I want to know how long the fly is. That’s what matter. And I think that’s your point too.
Dom
I don’t tie my own anymore but know from past experience that it is false economy to use cheap hooks, in my experience you only get what you pay for. I buy my flies from one or two local firms and they are excellent flies at a knock down price and have not let me down. Tight lines from Scotland.
Right on. It’s so easy to believe differently, though. It’s so tempting to keep trying to cut material costs.
Yes, yes, and yes. My god it’s dumb. I had to buy different brands of 16’s and 18’s last time around, and the 16’s ended up being twice the size of the 18’s. Now I’m trying to find a similarly-shaped hook to split the difference. What a chore. I hope other potentially influential voices take this up.
Right on. Well, share the article around and see if we can get the right people to listen.
Cheers.
Dom
New to tying (started in Jan 2021) but quite avid I think , having already caught trout on a dozen or more different patterns I’ve tied on several different fly sizes (nymphs, dries and buggers) and have tied over 500 flies. was quickly annoyed as I discovered that different name brands of hooks quoted as appropriate for the type of fly I was tying (and/or recommended by the recipe I was following) proved so different in size for the supposed same size hook: i.e. nymph 1x strong # 14! I quickly settled on 2 brands for consistency! Now , as noted, I still have to try to figure out which of my hooks best works as a substitute for THE hook recommended in a new “ recipe”! Like all other respondents, I’ve bought a number of boxes of 25 or more hooks which I’ll likely never use again! Take this as another vote for open information on hook dimensions!
Yes.
When I first started tying I felt the exact same way with hook sizes, and yes, just like you I have boxes of hooks that I bought my mistake because I thought they were what I want just from a different brand.
I also agree that there is nothing stopping fly tiers from measuring hooks and posting the measurements. I think that this would help tremendously. I would also add that yield strength for each hook should also be measured, this would be a great measurement to able to reference. I remember hooking into good fish, fighting, and releasing the fish, and then inspecting the fly to see the hook had yielded and I was probably one good head shake away from losing the fish. (I know yield strength isn’t something most people can measure at home, but it would still be nice to have.)
Nice commentary. All the best.
Oh, that would be nice. Yield strength would tell us SO much about whether to buy the hook or not. But I don’t know how to measure that.
As several have already stated here, this line is the key: “ For this alone, I’m buying and tying on more Ahrex hooks.” We ALL need to vote with our feet but unfortunately I’ve noticed in this new digital age companies that get the plug quickly run out. I hope Ahrex appreciates the plug & you get a link with royalties because you definitely have a following & street cred.
My issue as a ~1 year fly-tyer is I have some patterns that’ve bent out but I’m not sure when it happens which brand it was because I’m definitely still in the trial & error but at least guys that tie have some control over WHAT’s attached to their clinch knot; when you pick it up out of a fly shop bin to support a local shop there’s no telling what they used! Tight lines all.
Hi Tim,
For the record, I have no affiliation with Ahrex, and I don’t receive any money for that link. But for some others links on Troutbitten I do.
Cheers.
Dom
I do not understand this obsession with wanting to know the dimensions of a hook. I have been riding artificial flies to catch truhas for more than fifty years and I have never needed to know the length of a hook or the diameter. What I would like to know about a hook is its elasticity and resistance, but that is learned with experience. I also wanted to tell you that there are several manufacturers that do give the dimensions of their hooks such as Bimoo and others. Greetings Domenico. I like how you write.
Hi Manuel,
Thanks for the comment. Will you please link me to the companies that provide dimensions? I’m interested. You can email me domenick @troutbitten.com
Thanks.
Dom
I have agree. Asking for some sort way to know the size of the hook you are buying is well in line. The whole “hook size” being different from each other is a mess.
Yup
I use the “Bugometer” as my standard measure for hook/fly size. The Streamside Reference has a scale for standard dry fly, 2xl and 3xl lengths. There is also a “Benchside” reference that has a hook-length lookup table so if a book tells you the mature Green Drake nymph is 11mm long, you can see that is a size #10 std length hook.
I think the bugometer is neat. And it would be great if we could take that 11mm reference ad match it to a hook.
Dom
I keep it simple buy using the Al Caucci and Bob Nastasi “Hatches” or “Hatches II”, Hook Rationale chart to correlate hook shank size to insect sizing (millimeter). That is the standard, via Mustad specifications, that I compare every other manufacture against today. The inconsistent manufacture specifications pertaining to shank sizes (etc..) and direct comparison allow me to normalize my choice.
Hi there.
I don’t really understand your process for normalizing your choice. Do you mean you have to buy them first? If so, that’s my problem. I have no trouble seeing the sizes and comparing once the hooks are out of the package and in my hand. But we’d like to be able to know what we are buying before we buy.
Know what I mean?
Dom
Variations in hook size may cost us some money, and are only a problem if you believe that a trout will not eat your nymph if its is one or two millimeters shorter or longer than the natural. Since most nymph flies look nothing like the naturals, hook size is almost a non-issue. Natural dry flies vary considerably in size and so should my dry flies. Whenever I see a photo of an open fly box and each type of fly looks identical I wonder if the tier ever observed the real bugs. True standardization in hook sizing is a pipe dream and for the most part unnecessary as fly tying is an art not a science.
However, variations in hook wire strength (resistance to breaking or bending) can cost us the fish of a lifetime. Other non-measurable variables such as hook point shape and sharpness are also significant.
Bottom line is, identifying a small handful of strong reliable hook brands is not difficult. Whenever I stray from my reliable brands (TMC, Daichi, Firesticks, Fulling Mill) I know I’m rolling the dice and occasionally pay the price with a lost fish.
“Variations in hook size . . . are only a problem if you believe that a trout will not eat your nymph if its is one or two millimeters shorter or longer than the natural . . .”
Oh, no, no. Hook dimensions matter a lot more than that. Gap width, for example, is extremely important to me when tying streamers. For some patters, I want to be sure that I’ll have enough gap after applying thick body materials.
There are other considerations too. And they have little to do with any superstitions about a nymph being millimeters longer or shorter. The trouble is more complex than that.
Cheers.
Dom
There are things in this world that have been standardized. Sadly, fish hooks are not.
My wish for standardization would be for all tippet makers to agree to use the same interlocking spools. Yes, this is a minor quibble in the grand scheme of things, but it would be sweet.
HÅVARD EIDE has attempted the impossible over at https://flyhooks.org/