Defining fishing hooks since 1877

Hook Anatomy

Nature has created innumerable fish species for us to choose from when deciding to put fish on the menu. Through the ages, fishermen have invented and tried out quite a number of ways of catching fish — line and hooks being one method that has survived the centuries.

In this context, it is quite fascinating to think about the fact that many present-day Mustad hook patterns are results of “trial and error” from the Stone Age up to the present. Why a particular hook has been designed with a particular gape, bend, shank, barb and eye, etc., is a result of experience laboriously gained from the collective efforts of hundreds of generations of fishermen.

In terms of product development, the difference between our time and previous times is primarily a matter of speed and more sophisticated means of production and materials. Basic hook patterns, on the other hand, have not been subjected to much change.

The section on The History of the Fish Hook tells you quite a lot about the historical development of fish hooks; in this section we want to give you the basics of hook anatomy.

Getting to know hook terminology and what it stands for will make it easier for you when you need to find a particular hook for a particular purpose. Hook Sizes, Patterns and Parts In the illustration above, the various parts of the hook are shown with their proper names.

The two most important dimensions of a hook is its gape, the distance between point and shank, and the depth of the throat. Generous dimensions ensure deeper penetration of the point and better holding power of the fish. Hook MeasurementsUnfortunately, there is no uniform system of hook measurements. Visual familiarity with the various hook patterns is the only workable gauge for the serious angler. Although attempts have been made to set a standard by measuring the hook in fractions of an inch, the system has never been successful because it merely represents the length of the shank. A hook is really two-dimensional since the gape can vary greatly from one pattern to the next. Gape: The distance between point and shank Bite/throat: The distance from the apex of the bend to its intersection with the gape. Mustad measurements: Mustad Hooks range in size from 19/0 down to 32. Size 19/0 is the largest shark hook, size 32 is the smallest fly hook we make.

  • The Eye of a fish hook is the ring, hole or loop at the end of the shank through which the line or leader is secured.Common Types of Hook Eyes:

Ringed Eye:


An eye in which the wire diameter is constant and forms a circle perpendicular to the plane of the hook itself. The ball eye may be closed or open. The closed kind is tempered and therefore stronger; the open eye is usually found on cheap hooks.

Brazed Eye:

The gap of the eye of this hook is brazed to the hook shank. It makes a very strong eye, and one which will not cut the leader or line. Big-game hooks are usually brazed to ensure maximum strength.

Tapered Eye:

On a ‘tapered’ ring, the thickness of the wire is reduced. I t gradually tapers towards the end of the ring. This is done to reduce the weight of the hook and make it effective for dry-fly use.

Looped Eye:

The wire in the eye of the hoop runs back along the shank toward the rear of the hook. The end of this wire is usually tapered, although it can also be made untapered. Looped-eye hooks are traditionally used in making salmon wet flies.

Needle Eye:

So called because it is similar to the eye found on a needle. One advantage of the needle eye is that it may be easily strung through a natural bait without fouling. It is also strong.

Flattened Eye:

As an alternative to the eye, “Spade End” hooks are used. The end of the shank is flattened, and the fishing line is snelled/tied directly to the shank of the hook. The flattened area stops the knot from sliding off the hook. The flattened eye is used for medium-sized species in commercial fishing. Where natural bait, such as seaworm, is used, a hook may possess no eye at all, but simply a flattened end. Spade end hooks are extensively used by match anglers.

Common Eye Positions:

The position of the eye is an important factor when it comes to improving the hooking potential of artificial lures. “Straight” is the standard eye position. Here are three other variants:

Turned Up:

the eye is turned up from the shank

Turned Down:

the eye is turned down from the shank


the eye is parallel to the hook bend

The Shank is the leg of a hook which extends from the bend up to the eye. Hook shanks are manufactured in many different shapes. The most commonly used are:

Straight Shank:

The hook shank is straight from eye to bend.

Curved Shank:

Shanks are often curved for specific reasons, e.g. to accommodate a special fly imitation. Various fly hooks require the shank to be shaped so as to imitate the body of a special insect.

Sliced Shank:

In order to anchor baits, such as worms and soft baits, a barb or barbs are cut into the shank.

Specialised shank types:
  • Jig
  • Keel
  • Offset
  • Kink
  • Bent back

Bend Forged: In order to increase the strength of the bend (by approx. 25%), the wire of the bend is slightly compressed sidewise.