Tungsten Bead Size Chart: What Size Bead for Every Hook

The wrong bead size is the most common reason a good pattern fishes badly. Too big and the fly looks clumsy and rides nose-down. Too small and it never gets to the fish. Here is the chart we use at the Firehole bench, plus the two rules that make it work.

Rule 1: Match the bead to the hook

Two shapes, two jobs.

Slotted beads seat on jig hooks and heavy streamer hooks. The slot fits the bend of a jig hook so the bead locks in place and the fly rides point-up. If you tie euro nymphs on a 516 or a 551, you want slotted.

Round beads go on standard nymph and wet hooks, and on curved scud and pupa hooks. Straight or slightly curved shank, round bore, clean fit.

Dry flies, foam hoppers, and articulated shanks are not bead hooks. Leave them bare.

Rule 2: Size to the hook, and when in doubt, size down

Tungsten is dense, close to twice the weight of brass at the same diameter. That is why it sinks a fly so well, and it is also why an oversized bead looks bulky and throws off the profile. When you are between two sizes, drop to the smaller one. You keep the sink rate and lose the bulk.

The chart

Find your bead size, then read across to the hooks it fits. These are the ranges printed on our bead packaging.

Bead (mm)	Nearest inch	Hook size
1.5 mm*	~1/16"	#22 – #24
2.0 mm	5/64"	#18 – #22
2.5 mm	3/32"	#14 – #18
3.0 mm	~1/8"	#12 – #16
3.5 mm	9/64"	#10 – #14
4.0 mm	5/32"	#8 – #12
4.5 mm	~3/16"	#4 – #8

*1.5 mm is slotted only. The fractions are the nearest common size, not exact, so order by the millimeter. Tungsten is about twice the density of brass, so when you are between sizes, size down. The 4.5 mm is our largest Stone and tops out at a #4 hook; on streamer hooks larger than #4 it will not fit the wire.

If you want the naturalistic look, every size above is also offered in a speckled finish. Same sizing, same fit. Browse the Round Tungsten Stones and pick the color later.

Quick pairing by hook

A few of the hooks people ask about most:

• 516 jig (#4 to #24): slotted, 2.5 to 3.0 mm is the everyday size. This is the core euro-nymph pairing.
• 633 nymph (#10 to #22): round, 2.5 to 3.0 mm. A go-to bead-head nymph hook.
• 718 all-purpose (#4 to #24): round, 2.5 to 3.5 mm depending on the size you tie.
• 315 curved (#6 to #22): round, 2.5 to 3.5 mm. Heavier wire than most curved hooks, so it carries a bead and gets down.

Not sure which hook to start with? Our guide to choosing a fly tying hook sorts the whole line by what you tie.

Going heavier on purpose? The chart above keeps your fly balanced and natural. Euro nymphers sometimes want the opposite: the biggest bead a hook will take, to punch a fly to the bottom fast. A few jig hooks like the 535 are built for exactly that. We cover oversizing in its own guide: oversizing tungsten beads.

One more thing on weight

Because tungsten carries so much weight for its size, you can drop a size and still get down. On a size 14 nymph where a brass tyer reaches for 3.0 mm, a 2.5 mm tungsten Stone often sinks the same or faster with a slimmer profile. That is the whole point of tying with tungsten.

Match the shape, match the size, size down when you are unsure. Everything else is color.

Shop Round Tungsten Stones for standard nymphs, or Slotted Tungsten Stones for jig and euro patterns.