A fish hook, or fishhook, is a device for catching fish either by impaling them in the mouth or, more rarely, by snagging the body of the fish. Fish hooks have been employed for centuries by fishermen to catch fresh and saltwater fish. Fish hooks are normally attached to some form of line or lure device which connects the caught fish to the fisherman. There is an enormous variety of fish hooks in the world of fishing. Sizes, designs, shapes, and materials are all variable depending on the intended purpose of the fish hook.
There are a large number of different types of fish hooks. At the macro level, there are bait hooks, fly hooks and lure hooks. Within these broad categories there are wide varieties of hook types designed for different applications. Hook types differ in shape, materials, points and barbs, and eye type and ultimately in their intended application. When individual hook types are designed the specific characteristics of each of these hook components are optimized relative to the hook's intended purpose. For example, a delicate dry fly hook is made of thin wire with a tapered eye because weight is the overriding factor. Whereas Carlise or Aberdeen light wire bait hooks make use of thin wire to reduce injury to live bait but the eyes are not tapered because weight is not an issue. Many factors contribute to hook design, including corrosion resistance, weight, strength, hooking efficiency, and whether the hook is being used for specific types of bait, on different types of lures or for different styles of flies. For each hook type, there are ranges of acceptable sizes. For all types of hooks, sizes range from 32 (the smallest) to 20/0 (the largest).
Shapes and Names
Hook shapes and names are as varied as fish themselves. In some cases hooks are identified by a traditional or historic name, e.g. Aberdeen, Limerick or O'Shaughnessy. In other cases, hooks are merely identified by their general purpose or have included in their name, one or more of their physical characteristics. Some manufacturers just give their hooks model numbers and describe their general purpose and characteristics. For example:
- Eagle Claw: 139 is a Snelled Baitholder, Offset, Down Eye, Two Slices, Medium Wire
- Lazer Sharp: L2004EL is a Circle Sea, Wide Gap, Non-Offset, Ringed Eye, Light Wire
- Mustad Model: 92155 is a Beak Baitholder hook
- Mustad Model: 91715D is an O'Shaughnessy Jig Hook, 90 degree angle
- TMC Model 300: Streamer D/E, 6XL, Heavy wire, Forged, Bronze
- TMC Model 200R: Nymph & Dry Fly Straight eye, 3XL, Standard wire, Semidropped point, Forged, Bronze
The shape of the hook shank can vary widely from merely straight to all sorts of curves, kinks, bends and offsets. These different shapes contribute in some cases to better hook penetration, fly imitations or bait holding ability. Many hooks intended to hold dead or artificial baits have sliced shanks which create barbs for better baiting holding ability. Jig hooks are designed to have lead weight molded onto the hook shank. Hook descriptions may also include shank length as standard, extra long, 2XL, short, etc. and wire size such as fine wire, extra heavy, 2X heavy, etc.
Single, Double and Triple Hooks
Hooks are designed as either single hooks—a single eye, shank and point; double hooks—a single eye merged with two shanks and points; or triple—a single eye merged with three shanks and three evenly spaced points. Double hooks are formed from a single piece of wire and may or may not have their shanks brazed together for strength. Triple hooks are formed by adding a single eyeless hook to a double hook and brazing all three shanks together. Double hooks are used on some artificial lures and are a traditional fly hook for Atlantic Salmon flies, but are otherwise fairly uncommon. Triple hooks are used on all sorts of artificial lures as well as for a wide variety of bait applications.
Bait hook Shapes and Names
Bait hook shapes and names include the Salmon Egg, Beak, O'Shaughnessy, Baitholder, Shark Hook, Aberdeen, Carlisle, Carp Hook, Tuna Circle, Offset Worm, Circle Hook, suicide hook, Long Shank, Short Shank, J Hook, Octopus Hook and Big Game Jobu hooks.
Fly hook Shapes and Names
Fly hook shapes include Sproat, Sneck, Limerick, Kendal, Viking, Captain Hamilton, Barleet, Swimming Nymph, Bend Back, Model Perfect, Keel, and Kink-shank.
Points and Barbs
The hook point is probably the most important part of the hook. It is the point that must penetrate fish flesh and secure the fish. The profile of the hook point and its length influence how well the point penetrates. The barb influences how far the point penetrates, how much pressure is required to penetrate and ultimately the holding power of the hook. Hook points are mechanically (ground) or chemically sharpened. Some hooks are barbless. Hook points are also described relative to their offset from the hook shank. A kirbed hook point is offset to the left, a straight point has no offset and a reversed point is offset to the right.
Hook Point Types
Hook points are commonly referred to by these names: needle point, rolled-in, hollow, spear, beak, mini-barb, semi-dropped and knife edge. Some other hook point names are used for branding by manufacturers.
The eye of a hook, although some hooks are technically eyeless, is the point where the hook is connected to the line. Hook eye design is usually optimized for either strength, weight and/or presentation. There are different types of eyes to the hooks. Typical eye types include the ring or ball eye, a brazed eye-the eye is fully closed, a tapered eye to reduce weight, a looped eye—traditional on Atlantic Salmon flies, needle eyes, and spade end—no eye at all, but a flattened area to allow secure snelling of the leader to the hook. Hook eyes can also be positioned one of three ways on the shank—up turned, down turned or straight.
There are no internationally recognized standards for hooks and thus size is somewhat inconsistent between manufacturers. However, within a manufacturer's range of hooks, hook sizes are consistent.
Hook sizes generally are referred to by a numbering system that places the size 1 hook in the middle of the size range. Smaller hooks are referenced by larger whole numbers (e.g. 1, 2, 3...). Larger hooks are referenced by increasing whole numbers followed by a slash and a zero (e.g. 1/0 (one aught), 2/0, 3/0...) as their size increases. The numbers represent relative sizes, normally associated with the gap (the distance from the point tip to the shank). The smallest size available is 32 and largest 20/0.