In a previous post I talked about fly tying materials. And in another post I discussed the tools used to tie fishing flies. Today, I’d like to discuss the fish hooks used for fly fishing. Fly tiers use a wide variety of types of hooks. Let’s look into why they do that.

It’s All About Fooling the Fish

We tie the flies to mimic some sort of natural food. It might be an adult mayfly floating on the top of the water, a freshwater shrimp scurrying around the stream bottom, or a minnow swimming in the shallows. Each of these creatures has a different shape, and it’s much easier to tie a good imitation if the shape of the hook corresponds. So the hook for a fake minnow should be long and straight. The hook for the freshwater shrimp should be short and curved just like the creature’s body.

Size Matters!

Different sizes of the same style of hook, from size 10 (bigger) to 24 (tiny). The hooks are on quarter inch grid graph paper for size comparison. A size 20 hook is about a quarter inch long.
Hook sizes from 10 to 24 (missing size 22 because I don’t have any on hand.) For reference, the grid is 1/4″ per square. So yeah, that size 24 is pretty darn small.

Hook sizes are expressed as a number, with bigger numbers meaning smaller hooks. Hooks bigger than size 0 are numbered with multiple 0’s. So 3/0 is bigger than 2/0 but smaller than 4/0. Hooks that big are mostly used for saltwater fish or salmon. They only use the even numbers for hook sizes. You’ll never see a size 7.

The size of the hook refers to the size of the gap between the point (the sharp bit) and the shank (the straight bit). That gap size is consistent between styles of hook.

You choose the size of the hook based on the size of the bug you want to make. Many fly patterns are tied in a range of sizes so you can choose one that doesn’t look out of place among the natural creatures the fish are eating.

Three different hook styles, all in size 10, aligned on graph paper. Illustrates the consistent hook gap measurement between different styles.
All of these are size 10. The gap is the same, but the shanks are different lengths. Also note that the wire diameter is different for each one.

Style Matters Too!

There’s more to the hook than its size, of course. As I mentioned above, the length and shape of the hook should correspond to the length and shape of the creature your fly imitates.

But the hook can help the mimicry in other ways too. A heavier hook will help a minnow fly stay submerged. It will also survive snagging on submerged rocks better than a light hook would. Conversely, a fly imitating a newly-hatched mayfly has to float on the surface. So it needs a light hook. It won’t be snagging on rocks, so it just needs to be strong enough to hold the fish.

Who Makes Them?

There are a bunch of companies that make decent fish hooks. It isn’t exactly a new technology, after all. But Mustad, Tiemco, and Gamakatsu all have longstanding reputations. Eagle Claw is better known for bait hooks, but they make good fly hooks too. And Orvis has a good line of their own, as well as selling the other leading brands.

Barbed or Barbless?

A barbed and a barbless version of the same style of hook.
Look close, the size 12 doesn’t have a barb.

The barb on a hook is designed to keep the fish from dislodging the hook from its mouth and escaping. So why would you want a hook that doesn’t have one?

Firstly, barbs do a lot of damage to the mouth of the fish. Put simply, it makes a bigger hole going into the fish’s flesh. And it does even more damage on the way out. A barbless hook goes in and out like a needle.

That might not matter if you were going to eat everything you caught. But there are often legal limits on what sizes of fish you can keep. So if the fish is too small (or too big) you have to throw it back. And you don’t want to leave the fish badly wounded. The whole point of such rules is to let the fish live long enough to get big.

Speaking of legal requirements, some locations require barbless hooks, so you have no choice. If your hooks didn’t start off barbless, you have to flatten the barb with pliers before it’s legal to fish.

Further Complications

Hook styles can vary in other ways too. The point of the hook can be angled offline to the direction of the shank. They eye of the hook can be angled up, down, or not at all. The bend of the hook can be shaped in many different configurations. The hook can be made of carbon steel or stainless steel. You can get hooks in colors to match the fly to further disguise its nature.

The Saving Grace

Does all this sound really complicated? Well, if you were making up your flies from scratch, it would be. But you probably aren’t doing that.

People have been tying flies for a long time, and they’ve made up fly patterns to mimic about anything a fish could eat. The patterns that worked got written down and shared, and most people just follow them. And part of the recipe for each pattern is to specify the hook you’re using.

So in practice, you just consult the recipe and purchase the hook it calls for. Most patterns specify a range of sizes, so you’ll have to pick which you want. And you may consider a barbless version. But that’s about all the choosing you’ll usually have to do.

What If I Can’t Find It?

Sometimes a recipe will call for a brand the local store doesn’t stock. Before you order online, check a conversion chart. A lot of styles are made by more than one company under different model numbers, so a conversion chart can save the day.

I hope that helped make sense of it all. Until next time, may you have clear back casts and tight lines!