It’s rare for me to spend a day teaching or working in the shop without some poor soul asking me to explain the merits of this hook or that hook, and the reasoning behind why I might choose one brand or model over another. There’s good reason for this. Like tying thread (see my story “A Tangled Mess” in the Feb.-Mar. 2017 issue), hook sizing and nomenclature seem almost purposefully confusing, so let me give my best shot at clearing up some of that confusion.
To make sure I address all the right questions, as I write this article I have ten different size 14 hooks sitting on my desk. No two are the same size, length, or shape, and gazing upon them does nothing to shine any light on why they are all so different, so let’s start at the beginning and talk about how hook sizes work.
To understand how hook sizes and styles vary, it’s important to define the parts that make up a hook.
The hook gap (sometimes called the hook gape) is the distance from the point to the shank. The shank is the (usually) straight portion of the hook between the eye and the bend. Some hooks, however, have curved or humped shanks that are not straight at all. Curved-shank hooks mimic the shapes of many insect larvae and pupae, as well as the body shapes of crustaceans. A curved shank can orient the rear of the fly under the surface in floating patterns like the Quigley Cripple or the Klinkhamer Special.
The bend is where the shank starts to curve, as well as that entire radius encompassing the curvature down to the point. On curved-shank hooks, the shank and bend are often continuous with no clear line of distinction between where the shank stops and the bend begins.
The spear of the hook is the length of the tapered point to the barb or, in the absence of a barb, where it would be. The throat is the distance/depth from the point of the hook to the inside of the bend.
The hook eye is the loop at the front of the hook through which you tie your tippet. The eye can be turned up, turned down, or straight (ring eye). Turned-down eyes are the most common, though straight-eye hooks have gained significant popularity in recent years. Straight-eye hooks swim better and more in line with the tippet in the case of streamers, and in very small hook sizes, they obstruct the hook gap to a lesser degree. Up-eye hooks are common in heavier steelhead and salmon patterns and traditional trout fly patterns.
The barb is the small sticker angled away from the point, intended to make hook removal difficult. Even if you pinch the barb down (as I recommend) the remaining bump still helps anchor the point in a fish.
It also helps retain a dropper tied to the hook bend.
The point obviously is the sharp part, but it goes without saying that some hooks are sharper than others. Almost all hooks today are chemically sharpened, which means after the mechanical sharpening, the manufacturer uses an acid bath to dissolve the hook point, making it sharper.
With these terms defined and understood, let’s look at how they relate to one another, most specifically, the relationship between the hook gap and the shank.
Hook sizes historically are based on the gap of the hook. The size of the hook has nothing to do with the shank length, only the gap. So all size 18 hooks ought to have the same size gap, right? Well, in a perfect world they would, but in this day of unbridled design and outright lies, this “standard” is very loosely employed. To truly understand hook sizing, we’ve got to start off with an imaginary “standard” hook and extrapolate from there.
A standard hook is supposed to have a hook shank equal to twice the width of the hook gap. It is with this “standard” hook in mind that we can begin to understand the variations in gap and length and how they relate to one another.
As I mentioned earlier, this “standard hook” is really a fantasy, and in all my years of tying I have yet to come across this perfect example, but using it as a baseline is a good way to understand hook sizing. Once the baseline is established, hooks vary far and wide with extra-long (XL) or extra-short (XS) shanks, wide-gap (WG), extra-heavy (XH) or extra-fine (XF) wire sizing and offset points, among other variations.
Extra-long hooks have a shank length longer than two hook gap widths. These are often denoted as 1XL or 2XL, all the way up to 9XL in the case of some streamer-style hooks. The additional increments in shank length are based off the diameter of the hook eye in these cases, so a 2XL hook has a shank length of two hook gaps plus two eye lengths. Conversely, extra-short hooks are reduced by that same hook eye length increment, so a 3XS hook has a shank length of two hook gaps minus three eye lengths. These variations allow for flies of various lengths and shapes, and accommodate the addition of beads and coneheads without increasing or decreasing the hook gap disproportionately.
Lengthening and shortening shank lengths seems to make reasonable sense and is easy to follow once you have an idea of where things start, but when you start adding in gap width variations, everything goes to hell. Many hooks these days have a nonstandard wide gap, that is, a gap wider than the standard half a shank length (which could also be correctly construed as a shorter shank, just to confuse things further). Wide-gap hooks allow more room for thicker-bodied flies, and they increase the chances of the hook finding a home in a fish’s mouth. The increments in which a hook gap is increased are by hook sizes. For instance, a 1X wide-gap size 14 hook should have a gap equal to that normally found on a size 12 standard hook. A 2X wide-gap size 14 should sport the gap normally found on a size 10 standard hook, and so forth. For the record, I have never encountered any hooks labeled with a narrower-than-standard gap, though some of the wide variety of available hook bend shapes certainly contribute to narrowing the hook gap.
To add complexity, also consider the variations in wire sizing. Some hooks are made of wire heavier (X-heavy) or lighter (X-fine) than what would be considered standard, so a size 14 1X-heavy hook is made from wire normally used on a standard size 12 hook, and a 2X-heavy size 14 would be made of wire typically used in a standard size 10 hook. That same size 14 in 1X-fine would be made from wire normally used in a standard size 16. Obviously, heavy wire hooks are stronger and physically heavier for bigger fish, or for sinking flies quickly. Lighter wire can be advantageous in keeping small, delicate dry flies floating. The trade-offs are that the wire size can get too big to provide good penetration on a hook-set, or in some cases the wire could be too light to stand up to larger fish and strong tippets.
With the basic nomenclature and sizing understood, let’s move on to the difference between good hooks and bad hooks. In nearly every case, it boils down to the tempering and forging process used to strengthen the wire. Tempering is a complicated heat-treating process that renders the steel wire used to make hooks both stronger and more elastic. A batch of hooks with a bad temper can be brittle and break easily, or they can be soft and bend out of shape on the fish of your dreams.
I won’t pretend to know the ins and outs of the entire tempering process, as I am just a guy who has wrapped a few miles of thread around hooks and thrown them at an awful lot of fish. I can say that I have yet to find an inexpensive hook that is worth tying a fly on. Quality hooks don’t straighten, bend, or break as easily as cheaper hooks. To put it in perspective, expensive hooks are still the cheapest pieces of tackle you own, and also the most important. I can’t think of anything worse than tying a bunch of great flies on garbage hooks.
The influence of competitive fly fishers in recent years has made competition-style hooks extremely popular. According to the rules of FIPS/Mouche, the official governing body for international fly-fishing competitions, the hooks in these contests must be completely barbless. While the competition hooks that have evolved from these events come in all shapes and sizes, they often feature a very wide gap, and a long point and spear to better hold the fish in the absence of a barb. For some reason, many of them tend to be black, a feature that adds a degree of stealth and dare I say panache if not for any more practical advantage.
I would be remiss if I did not mention the growing popularity of jig-style hooks—also adopted from the competitive fly-fishing scene. Flies tied on jig hooks with heavy tungsten beadheads are filling fly boxes across the country. Jig hooks for fly fishing are typically barbless, and are available with the hook eye set at 60 degrees or 90 degrees in relation to the hook shank. The 60-degree versions have a more exposed hook gap, but require a slightly heavier bead to keep them riding with the hook point up. Regular 90-degree jig hooks ride hook point up more consistently, but are more prone to break at the bend due to the aggressive reshaping of the hook.
Jigs are very effective at hooking fish in the top of the snout, a perfect place to find good purchase and steer the fish during the fighting and landing process. That’s one reason competitive fly fishers use them. The biggest advantage, however, is that they are less prone to snagging the bottom.
I hope that the preceding has helped provide a general understanding of how hook proportions and shapes affect fly design and your own tying. The hook is the foundation of what you build, so it’s important to choose the right hook for the job. As with thread, there is no real base industry standard, so styles and baselines range widely among manufacturers.
These rules of thumb tend to apply broadly to all hooks, but are more accurate when taken into consideration among hooks of the same brand, and even then there are always a few outliers. This broadly sweeping guideline is just that, and should be used as such. Good luck!