Nymphs · Sizes #4-18
The Daiichi 1720 is a barbed nymphs hook available in sizes #4-18. It's built around a long shank built for extended bodies: damsel nymphs, larger stonefly imitations and small streamers, paired with heavy wire, one step stronger than standard, adding a little sink rate and useful margin when fishing for larger fish. Tyers reach for it most often when working on nymphs, beadheads, subsurface. The sections below break down what each specification actually means at the vice, which patterns suit it, and which hooks from other manufacturers you can substitute when it's out of stock.
Shank length (3XL). This hook has a long shank built for extended bodies: damsel nymphs, larger stonefly imitations and small streamers.
Wire strength (1XH). It's made from heavy wire, one step stronger than standard, adding a little sink rate and useful margin when fishing for larger fish.
Bend and gape (Round). The 1720 uses a round bend that distributes pressure evenly and holds well.
Eye type (Down). It's finished with a down eye, the traditional choice, which sets a good hooking angle for dry and wet flies fished on a tippet.
Barbed. This is a barbed hook. Many competition rules and an increasing number of catch-and-release fisheries require barbless, so check local regulations — the barb can be pinched down with flat-jawed pliers before you dress the hook.
The Daiichi 1720 is tagged in the Woolly Bug database for nymphs, beadheads, subsurface. Patterns that sit naturally on this hook include Hare's Ear Nymph, Pheasant Tail Nymph, Copper John, Beadhead Hare's Ear, Beadhead Pheasant Tail, Diawl Bach. Because the hook's proportions drive the finished fly's silhouette, it's worth matching the pattern's intended shape to the shank rather than forcing a recipe onto the wrong blank.
The 1720 runs from size 4 through 18. The smaller end of the range (down to size 18) covers midge and small mayfly work, where fine tying thread and sparse dressings matter more than bulk. If you're buying this hook for the first time, the mid-range sizes see the most use at the vice, and tracking exactly which sizes you own is where an inventory app earns its keep — it's the detail most tyers forget at the fly shop counter.
These hooks match closely on the specifications that determine a fly's proportions and behaviour, so they work as substitutes.
If the Daiichi 1720 is out of stock, the closest match in the database is the Daiichi 1718. When substituting, the specifications that matter most are gape and shank length — these determine whether the finished fly keeps its intended proportions. Wire strength is the next consideration, since it changes how the fly sits in the water: a heavier wire will sink a pattern that was designed to float. Eye type is usually the most forgiving difference, though switching to or from a jig eye changes how the hook rides entirely.
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Download FreeThe Daiichi 1720 is a nymphs hook used for Nymphs, Beadheads, Subsurface. It's available in sizes #4-18 with a 3XL shank and 1XH wire.
The closest equivalents are: Daiichi 1718. These match on the specifications that matter most — shank length (3XL), wire strength (1XH) and bend (Round).
The Daiichi 1720 is barbed. Barbed hooks can be pinched down with pliers where barbless is required by competition rules or fishery regulations.
It's available in sizes #4-18.
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