Nymphs/Emerger · Sizes #12–20
The Firehole 316 is a barbless nymphs/emerger hook available in sizes #12–20. It's built around a continuous curved shank that follows the natural arc of scuds, pupae and emerging insects — the curve does much of the shaping for you, paired with standard wire — a balance of strength and weight that works across most freshwater applications. 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 (Curved). This hook has a continuous curved shank that follows the natural arc of scuds, pupae and emerging insects — the curve does much of the shaping for you.
Wire strength (Std.). It's made from standard wire — a balance of strength and weight that works across most freshwater applications.
Bend and gape (Wide). The 316 uses a wide gape, improving hook-up rates and leaving clearance for a bulkier dressed body.
Eye type (Straight). It's finished with a straight (ring) eye, the most versatile option — it keeps the fly tracking in line with the leader, which suits nymphs and streamers.
Barbless. This hook is barbless from the factory, so it's ready for competition use and catch-and-release waters, and it does noticeably less damage to fish. Keep a steady line tension when playing a fish, as barbless hooks drop out more readily on slack.
The Firehole 316 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 316 runs from size 12 through 20. The smaller end of the range (down to size 20) 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 Firehole 316 is out of stock, the closest match in the database is the Firehole 315. 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.
Log every hook, material and pattern on your bench — free on the App Store.
Download FreeThe Firehole 316 is a nymphs/emerger hook used for Nymphs, Beadheads, Subsurface. It's available in sizes #12–20 with a Curved shank and Std. wire.
The closest equivalents are: Firehole 315, Fario FR100BL, Firehole 718. These match on the specifications that matter most — shank length (Curved), wire strength (Std.) and bend (Wide).
The Firehole 316 is barbless. That makes it suitable for competition use and catch-and-release fisheries without modification.
It's available in sizes #12–20.
Woolly Bug