The two most common sizes of fishing hooks in North America and Europe are the size 4/0 and the size 6/0, with a few other sizes in use. The 0 designation refers to the diameter of the hook’s shank. The smaller number is more internal than external, while larger numbers are more external (i.e., larger on your thumb).
Fishing hooks are manufactured in an assortment of shapes and sizes. Hooks can range from less than a millimeter all the way to the largest hook on Earth, which measures 8 feet 2 inches (2.49 meters) long and weighs over 230 pounds (100 kilograms).
Hooks are commonly divided into three categories: “general-purpose”, “medium”, and “special” – though hooks are not divided this way for legal reasons. The term general-purpose refers to hooks with medium-wide gapes that can be used for most fishing. This includes many of the most common bait fishing hooks like Aberdeen, circle, snap, and round-shank hooks. Medium-wide gapes are those that are not so wide and can be used for many varieties of rig fishing. Special hooks exist for such uses as fly fishing, with sizes ranging from 0 to 3/0.
In Europe and the United States, general-purpose hooks are often called needlepoint or tapered, while in Great Britain they are commonly referred to as “spoons”. Medium-sized hooks include the “U” (UK), Italian, Spanish, and Uruguayan style wavy point hook; the “B” (Bangladesh), Turkish (light tackle), and American style round-shank hook – derived from the treble hook shape. Special hooks include the classic Haydon gape and the Japanese Octopus hook, both of which have long straight shanks and are extremely sharp. These hooks are often used for bait fishing and fly fishing, respectively. Special-purpose hooks cover a wide range of shapes and sizes including many designed for specialized types of catch, such as catfish in southern states in the US, where large-sized “C” hooks are popular; or to targeting specific species such as whiting in Australia were extremely heavy “G” size barbed J hook with long shank points are used.
The use of different types of the hook is governed by law. For example, in most European countries, the use of a circle hook is required by law for catch-and-release fishing of big-game fish like Salmon or Sea Trout.
With the invention of the nylon fishing line, the mono-filament braided line offered better sensitivity than wire. In the 1950s several developments occurred that changed the shape of the modern fishing hook. The birth of “new” or “modern” trout hooks (MX series) came about due to the development of new technologies and techniques in manufacturing wire. Hooks became thinner and stronger with a more substantial wire that was more pliable and less stiff. They evolved from double-eye styles to the “single-eye” style categories. Another important component to modern hooks is other materials used in the construction of the hook itself, such as “saitered” wire for sharpness and action similar to rasps.
The International Tuna Harvesters Association holds a World Record for the longest fish caught with a hook in 2004. The World Record was set by Tom Lavell and Rodney Hansen of Santa Monica, California when they reeled in a 6’2½” Black Marlin weighing 300 lbs.
Hooks have changed little in shape or appearance since they were first made. This is not the case for hooks that are made for specialized uses. For example, meat hooks have been specially modified to handle the tough hide of game animals. Hooks used for catching catfish feature a special design to firmly grip the slippery fish and prevent it from slipping off the hook.
The earliest known hooks were made approximately 4000 years ago by the Bronze Age peoples of northern Europe. The first fishing tools were made out of wood, bone, or antlers, much like those used in previous centuries. Early hooks were mostly treble or single hooks, meaning they had two or three points on them. They were used with either bait or a lure tied to them via a short line.
Modern-day fishing hooks are still made from metal, usually stainless steel. The point of the hook is also made from metal, which used to be a single barbed in some cases. Most anglers prefer double-barb hook points for their versatility, and because they are easier to remove once the fish has been landed. Hooks are manufactured in plain finish or coated with different materials for specific uses, such as copper for catfish or hard plastic for saltwater fishing. The hardness of a hook is dependent on its intended use: Fly-fishing hooks are normally much harder than those used for bait fishing. Hooks are also graded on toughness and weight. A standard is that species such as salmon and cod will always take a certain type of hook, even if it is more suited for another species.
Hook sizes are measured in millimeters from the tip of the point to the shank, excluding barb length. The hook size directly reflects how big or small a fish it is designed for. For example, a size 4/0 hook would be about 1 mm thick at its widest point, whereas a 8/0 would be about 8 mm thick with a 1 mm body thickness. The head size of the hook is measured between the point and the shank. The standard sizes are as follows:
Large-sized hooks can be very strong. However, they are also both heavy and bulky for smaller fish to handle in their mouths so they are not as commonly used. These hooks usually have a tapered taper with a wider tip which is used when fishing through dense vegetation to catch large fish such as salmon. It is very important to completely remove this point to prevent it from getting stuck in the foliage, which can often happen when fishing through thick bushes or overhanging tree branches.
Hooks are also often used to catch insects, mostly as a form of fishing bait. The hook itself is either sewn or tied onto the body of the fly or lure with material such as silk, which is strong yet sensitive to touch.