How to tie aDouble Surgeon’s Knot

The quickest strong way to join two fishing lines: overlap the ends, tie a double overhand with both lines at once, pull tight, trim.

Procedure: Line-to-line join
Passes: 2 (3 for slick line)
Overlap: About 15 cm (6 in)
Difficulty: ●●○○○ easy

Begin step 1 Watch at 4× Pin it

A finished double surgeon’s knot: a steel-blue main line and an apricot leader joined in a compact barrel of two turns, both tag ends trimmed short

Fig. 1 · two lines, one barrel; both tags trimmed

00Full procedure · 9 s at 4×

Start to finish in nine seconds

Overlap, loop, through twice, pull all four, trim. Watch it once whole, then take it step by step.

One beat per step · the dot follows the clip

01Pre-op · before you start

Two lines, side by side

A steel-blue main line and an apricot leader laid side by side, their ends overlapping before the knot is tied

Fig. 2 · the leader slides in alongside the main line’s end

Same size or not
It joins lines of similar or quite different diameters: tippet to leader, leader to main line.
Overlap about 15 cm
Lay about 15 cm (6 in) of each end side by side, pointing opposite ways. Too short and you run out of tag.
Wet before pulling tight
A little water or saliva lets the turns slide home without friction heat weakening the line.

Pairings

Same size	Tippet to tippet, mono to mono	2 passes
Thin to thick	Tippet to leader, leader to line	2 passes
Slick line	Fluorocarbon or braid in the join	3 passes

02Procedure · each clip loops

Five steps to a double surgeon’s knot

Overlap the ends
Lay the end of the leader alongside the end of the main line so they overlap by about 15 cm (6 in), the two ends pointing opposite ways.
NotePinch the overlap between finger and thumb. From here on, treat the two lines as one.
Make a loop
Holding both lines together, curl the doubled part up and back over itself to form a loop.
NoteKeep the loop roomy: both ends have to go through it twice.
Through twice
Take both ends together round and through the loop, then through again: a double overhand in two lines at once.
NoteThe leader goes through whole, so tie with a short leader or tippet and the main line’s end.
Pull all four
Wet the knot, then pull all four strands at once, both lines on each side, so the turns bed down into a neat barrel.
NotePull slowly and evenly. Water cuts the friction heat that can weaken nylon line.
Trim the tags
Trim both tag ends close to the knot, one on each side.
NoteLeave a stub of about 2–3 mm (⅛ in), so the ends can’t creep back through.

Closed: one barrel, two lines out, two short stubs

03Post-op · check before you fish

Two lines joined in a neat barrel

One compact barrelThe turns bedded side by side, no loose loop standing up.
Opposite ways outMain line leaves one side, leader the other, in a straight line.
Two short stubsOne trimmed tag on each side, about 2–3 mm long.
Holds a hard pullPull the two lines apart firmly before you trust it with a fish.

04Variants · finishing

The triple, and a clean trim

Variant · 3 passes

The triple surgeon’s knot

Tie it exactly the same way but take the ends through the loop a third time. The extra turn gives slick lines more to grip, so the knot doesn’t slip as it is pulled tight.

Double · 2 passes

Triple · 3 passes

Use it for fluorocarbon, which is stiff and slippery, and for joins involving braid.
The barrel is a little longer and bulkier; it still passes through most rod guides.
Wet it well: three turns create more friction as they bed down.

Finishing · the tags

Trimming the tags

Only trim once the knot is fully pulled down. Cut both tags, the main line’s on one side and the leader’s on the other, with sharp nippers or small scissors.

2–3 mm stubs, one each side

Leave a 2–3 mm (⅛ in) stub: flush cuts can creep back through under load.
Square, clean cuts don’t snag weed or rattle through the guides.
Don’t burn mono tags: the heat can weaken the knot right beside them.

05Examine · interactive 3D

Examine it from every side

Drag to turn the knot, pinch in on the turns, scrub back to any step, or glow the main line to trace it through the loop.

Live model · SK-2Drag · pinch · scrub

Interactive 3D model of the double surgeons knot, tied step by step

· Drag to turn · pinch to zoom

0:00

06Indications · common uses

Common uses

USE 01

Leader to tippet

Add fresh tippet to the end of a fly leader as it gets cut back.

USE 02

Building fly leaders

Join sections of stepped-down diameter into a hand-tied tapered leader.

USE 03

Mending a broken line

Rejoin a snapped line on the water in seconds, with no tools.

USE 04

Joining two cords

Any two strings or thin cords: kite line, whipping twine, craft cord.

How to tie a double surgeon’s knot in 5 steps: overlap the ends, make a loop, through twice, pull all four, trim the tags

07Take away

Keep the card

All five steps on one card. Pin it, or keep it with your fly box for the next time you add tippet.

Pin it