Slotted Tungsten Firehole Stones™

Tungsten beads slotted to seat clean on a jig hook. No wobble, no fight to get them on, and the same weight bead to bead.

At a Glance

• Pack: 24 beads. 18 at 4.0mm, 12 at 4.5mm
• Material: 95% tungsten alloy (W/Ni/Fe)
• Density: About 18 g/cm³, roughly 1.6 times lead
• Slot: Precision cut for 60 and 90 degree jig hooks
• Bore: Clean and uniform, no thread fraying
• Sizes: 1.5mm to 4.5mm
• Colors: 23

Ties Well As

• Euro nymphs and perdigons
• Anchor flies
• Jig-style tactical patterns
• Any pattern that needs to ride point-up

From the Bench

Slot size matters more than diameter. A slotted bead will seat on a jig hook that a round bead of the same diameter will never clear. At the top end, 4.5mm caps out around a #4 and will not fit larger hooks.

Slotted runs 0.03 grams at 1.5mm up to 0.72 at 4.5. That is a shade heavier than a round bead the same size, because the smaller through-bore leaves more tungsten in the bead. The gap is a few hundredths, close enough that you can move a pattern between a jig hook and a standard nymph hook without redoing the math.

The Stone Stack has every weight, and how these stack with Bug Bands and Tear Drops.

On the Metal

Tungsten beads are made from tungsten heavy alloy rather than pure tungsten: tungsten powder sintered with a few percent of nickel and iron. Pure tungsten is brittle and difficult to work, and the binder is what makes a bead you can handle without it chipping.

Ours runs 95% tungsten, which puts it at about 18 g/cm³, roughly 1.6 times the density of lead. The category generally sits between 90% and 97%, a spread of about a gram and a half per cubic centimetre. On a 3.0mm bead that is a difference of about two hundredths of a gram, where going up one bead size is twelve hundredths. Size moves weight roughly six times harder than purity does.