Double surgeon's

What it joins

The double surgeon's knot joins two lines end to end. Its everyday job is adding a new piece of tippet to a leader, and that is how every source we read frames it first. Scientific Anglers calls it the easiest and fastest fly fishing knot for attaching the tippet to the leader in all kinds of conditions. Orvis says it is for connecting sections of tippet. Animated Knots says it is useful to join two fishing lines of moderately unequal size, a tippet to a leader for example, and that it is usually used to join two pieces of monofilament.

The knot itself is simple. NetKnots describes it as two overhand knots with the entire leader pulled through the knot each time. Lay the two lines side by side, tie an overhand knot with both of them treated as one strand, pass the same pair through the loop a second time, and draw it tight. A third pass makes the triple surgeon's.

That construction has one consequence that decides when you can use it: one of the two lines has to pass all the way through the loop, twice. Animated Knots says plainly that the knot can only be tied with a tippet for that reason. A short piece of tippet goes through easily. A line still attached to a full spool does not.

Basis: consensus (Scientific Anglers, Orvis, Animated Knots, NetKnots)

Lines and the diameter spread

• Mono to mono and tippet to leader: yes. This is the job it is made for.
• Fluorocarbon tippet to a nylon leader: yes. Tom Rosenbauer, answering MidCurrent's panel, ties a triple surgeon's when going from fluorocarbon to mono. NetKnots says the knot can join lines of different materials.
• Braid to a fluorocarbon leader: it has been tested that way, and held well (see the tests below), but none of the tying guides we read recommends it for braid. Our reading: the braid side is usually line still on the spool, which cannot pass through the loop, so the knot rarely fits the job.

How far apart can the two diameters be? The sources describe it in words, not numbers:

• Orvis: sections of tippet that are similar in diameter or that differ greatly in diameter.
• NetKnots: lines of equal or unequal diameter.
• Animated Knots: lines of moderately unequal size.

None of the pages we read gives a maximum difference in thousandths of an inch or in X sizes for the surgeon's. The published number is on the other side of the comparison. In MidCurrent's panel on blood knot versus surgeon's, Rosenbauer uses a blood knot if the diameters are within .001 inch and a triple surgeon's if they are not; Lori-Ann Murphy refers to the 2-size grace rule she uses with blood knots. So the working reading, which is ours: when the two lines are more than about one X size apart, the surgeon's is the knot that tolerates it, and how far past that it holds is not published.

Basis: consensus on the wording (Orvis, NetKnots, Animated Knots); official on the quoted thresholds (MidCurrent panel); editorial on the braid reading and the working reading

Best uses

• New tippet on a tapered leader, on the water, in bad light, with cold hands. NetKnots suggests it for exactly that: low light, cold hands, or when you need to get back in the water fast.
• Stepping down from one tippet size to a finer one, for a dry-dropper or indicator nymphing rig, where the second section joins the first.
• A fluorocarbon tippet section on a nylon leader.
• A fixed loop at the end of a leader or butt section, using the same knot tied in a doubled line: the surgeon's loop, below.

Basis: consensus (NetKnots, Scientific Anglers, Orvis, MidCurrent); editorial on the rig list

Difficulty

Easy. Animated Knots calls it one of the easiest knots to learn; Global FlyFisher's leader page calls it a quick and easy knot to tie. There are no wraps to count around another line, only two passes through one loop. In our reading of the steps, the two things that go wrong are letting the two lines separate as they pass through the loop, which is why Orvis wets them to keep them together, and seating it without pulling all four ends, which Animated Knots and Scientific Anglers both specify.

Basis: consensus (Animated Knots, Global FlyFisher); editorial on the failure points

How to tie it

The steps assume the tippet, the new and shorter piece, is in your left hand, which is how Orvis sets it up. The "leader" is the line running back to the fly line; its "tag end" is the short end you are joining to. The tippet's "standing part" is the long piece you are adding.

Watch it tied. Animated Knots' Surgeon's Join page steps through the knot frame by frame, and Orvis's surgeon's knot video shows it tied in tippet. We read both alongside the steps below, and they agree.

1. Lay the leader's tag end and the tippet side by side, pointing in opposite directions, so they overlap. Orvis gives 4 to 6 inches; Scientific Anglers about 6 inches.
2. Pinch the two lines together near one end of the overlap and form a loop with the overlapped section, both lines together. Orvis pinches the junction of the loop with the right thumb and forefinger.
3. Tie an overhand knot with the pair: pass the leader's tag end and the whole length of the tippet through the loop, treating them as a single strand. Scientific Anglers: the entire length of the tippet must be passed completely through the overhand knot loop. Do not tighten it.
4. Pass the same pair through the same loop a second time. Orvis's tip: they stay together more easily if you wet them with saliva. That is the double surgeon's. For the triple, pass them through a third time.
5. Wet the knot. Hold the leader and the tippet's tag on one side and the tippet and the leader's tag on the other, and pull all four ends at once. Animated Knots says to set it by pulling on all four ends, and Scientific Anglers says pull all four ends simultaneously to snug the knot tight.
6. Check that all four strands are snug, then trim both tags. Orvis trims them as close to the knot as possible.

The sources split on the speed of the final pull. Orvis says to pull quickly and tightly. Scientific Anglers' general rule for all knots is to moisten them, tighten them slowly, and test every knot by pulling on it, and Global FlyFisher notes, about leader knots, that heat from friction weakens leader material. Our advice, given that split: wet it and draw it down smoothly and firmly rather than with a snap.

Basis: consensus (Orvis, Scientific Anglers, Animated Knots, NetKnots); editorial on the pull speed

Double or triple

The third pass is the only variant that matters, and the sources disagree on what it buys.

• NetKnots: the extra wrap adds some security but makes the knot bulkier.
• Global FlyFisher (Steve Schweitzer): a double surgeon's is ample for most tippet to taper connections, and a triple adds extra insurance against slippage. The same page reports that Jim Vincent of RIO recommends the blood knot for tippet thicker than .007 inch (4X) and the triple surgeon's for tippet finer than that. That is Global FlyFisher's account of his research; we could not find RIO's own page saying it.
• Animated Knots, on the loop form: an extra turn gives minimal additional benefit and adds bulk.

Our position: tie the double for routine tippet changes at 4X and heavier, and the triple in fine tippet and in fluorocarbon to nylon, where the sources above lean toward it. That is our reading of them, not a tested rule.

Basis: consensus on the variant; editorial on the recommendation

What the published tests show

No test we could read isolates the plain double surgeon's knot in tippet and gives it a percentage. These are the tests that put a surgeon's knot beside the blood knot or the double uni:

Notes on reading them:

• Field and Stream calls its knots "3-turn" and "4-turn" surgeon's knots and does not say whether a turn is one pass through the loop. If it is, the 3-turn knot is the one NetKnots and Animated Knots call the triple surgeon's.
• In the same fluorocarbon-to-mono section, both the Field and Stream page and its Popular Science reprint print the back-to-back uni figure as 6%. We print it here because it is what the test says, and we cannot tell whether it is a typo.
• Rowland reports pounds at break, not a percentage of the unknotted tippet, and one pull per knot per round.
• Salt Strong did not test the surgeon's, so the surgeon's and the double uni have never met in a mono-to-mono test we could find. The only direct comparison is Field and Stream's braid-to-fluorocarbon pull, where the 4-turn surgeon's beat the back-to-back unis, 80% to 75%.

So: against the blood knot, a surgeon's knot lost both times it was tested, by 18 points in Field and Stream's fluorocarbon-to-mono pull (a 3-turn surgeon's) and by 1.9 lb in Rowland's tippet retest (a triple). Against the double uni, it won the one comparison there is. NetKnots says a properly tied surgeon's approaches 100 percent line strength, and Animated Knots' loop page repeats that some sources claim a high proportion of rated strength; neither gives a method, and neither number appears in the tests above. MidCurrent's panel adds a caution from Ted Leeson, relaying a DuPont contact: the relative strength of the two knots varies a good bit with the person tying them. His advice is to go with what you tie best, unless you are building leaders, where there is no substitute for a blood knot, at least in the butt and midsections.

Testing methods vary in ways that change the numbers: percentage of rated or actual break strength, machine or hand pull, the number of pulls, wet or dry, and the brand of line. Treat any single figure as a data point.

Basis: official on the test figures, each from the named test; editorial on the summary

The surgeon's loop

The same knot tied in a doubled line makes a fixed loop at the end of a line. Animated Knots describes it as essentially a double overhand knot tied quickly at the end of a line, often used for a loop-to-loop connection. Orvis's double surgeon's loop:

1. Bend a loop in the leader so the tag end overlaps the standing part by about 5 inches.
2. Treating the doubled line as one strand, tie a loose overhand knot with the loop.
3. Pass the loop through the overhand a second time, making a double overhand.
4. Lubricate the knot with saliva, then pinch the tag and the standing part together in one hand and pull the loop the opposite way with the other. Trim the tag.

Orvis says it is easier to tie than a perfection loop in heavy tippet, and gives its drawback: the standing part of the leader is cocked off to one side. Animated Knots says a third pass gives minimal additional benefit and adds bulk. See loop-to-loop for joining two loops.

Basis: consensus (Orvis, Animated Knots)

When it is the wrong knot

• Building a leader, or joining butt and midsections of similar diameter: a blood knot. Leeson, on MidCurrent's panel, says there is no substitute for it there, Animated Knots calls the surgeon's rather bulkier than the blood knot, and Orvis calls it not as clean as the blood knot.
• Two lines both still attached to something long, such as main line on a spool: you cannot pass the spool through the loop. Use the double uni.
• Braid to a fluorocarbon or mono leader that has to pass through the guides: the Alberto, or the double uni. The surgeon's tested well in braid in one pull, but the braid side is on the spool, so the knot does not fit the job.
• When the line must come off straight: Animated Knots says the surgeon's creates a slight angle in the line, and Orvis's loop version leaves the standing part cocked to one side.
• Line to a hook or fly: a terminal knot, never a join. The improved clinch or non-slip loop on tippet, the Palomar on conventional tackle.

Basis: consensus; editorial on the recommendations

Testing and trimming

• Pull it once, hard, after trimming. Scientific Anglers' rule for every knot is to test it by pulling on it.
• Look at it. A compact double overhand with all four strands snug is right. A loose strand, or one line that slid out of the pair while passing through the loop, is a retie.
• Trim the tags close; Orvis says as close to the knot as possible.
• Retie a surgeon's that has caught on weed or rock, or that has started to look twisted; that rule is ours.

Basis: consensus (Scientific Anglers, Orvis); editorial on the retie rule

Rigs and techniques that use it

• New tippet on a tapered leader for trout on the tailwaters, such as the Cumberland River tailwater. See leaders and tippet for sizing the pieces.
• The step-down in a dry-dropper or indicator nymphing rig.
• A fluorocarbon tippet section on a nylon leader, including on streamer fishing leaders.
• A surgeon's loop at the end of a butt section or leader for loop-to-loop changes.

Basis: editorial

What we don't know yet

• A maximum diameter difference for the surgeon's, in thousandths of an inch or in X sizes, from a maker or a named test. The sources describe it only in words. Status pending.
• A published test of the plain double surgeon's knot in tippet, as a percentage of unknotted strength. The tests we found are of 3-turn, 4-turn and triple versions. Status pending.
• RIO's own statement of Jim Vincent's 4X recommendation. We found it only as Global FlyFisher's account. Status pending.
• Fly Fisherman's tippet test, which forum posts describe as comparing knots including the triple surgeon's. We could not find the article itself, so it is not used here. Status pending.
• Whether Field and Stream's 6% figure for back-to-back unis in fluorocarbon to mono is a typo. Status pending.
• A head-to-head mono-to-mono test of the surgeon's against the double uni. We did not find one.

Sources and how confident we are

Claim	Basis	Confidence
Tying sequence	Orvis, Scientific Anglers, Animated Knots, NetKnots	High
Diameter tolerance	Words only, no published number	Medium
Strength against the blood knot	Field and Stream; Rowland	Medium: few tests, methods differ
Strength against the double uni	Field and Stream, one pull set	Low

Sources

• Surgeon's Knot (video) — Orvis — for tippet sections of similar or very different diameter; strong and easy, not as clean as a blood knot; 4 to 6 inch overlap; two passes; wet with saliva; pull quickly and tightly; trim as close as possible.
• Double Surgeon's Loop (video) — Orvis — the loop steps, about 5 inches of overlap; easier than a perfection loop in heavy tippet; the standing part cocked to one side.
• Fly Fishing Knot Tying Basics — Scientific Anglers — the easiest and fastest tippet-to-leader knot; about 6 inches of overlap; the whole tippet through the loop; pull all four ends; moisten, tighten slowly and test every knot.
• Surgeon's Join — Animated Knots by Grog — moderately unequal sizes, tippet to leader; usually two pieces of monofilament; can only be tied with a tippet; set by pulling all four ends; bulkier than the blood knot and a slight angle in the line; the triple.
• Surgeon's Loop — Animated Knots by Grog — the loop as a double overhand for loop-to-loop; the triple giving minimal additional benefit; the "some sources" strength claim.
• Surgeon's Knot — NetKnots — two overhand knots with the leader pulled through; equal or unequal diameter and different materials; low light and cold hands; the triple adding security and bulk; "approaches 100-percent line strength" (no method given).
• Which Knot: Blood Knot or Surgeon's? — MidCurrent — Rosenbauer's .001 inch rule and his triple surgeon's for fluorocarbon to mono; Murphy's 2-size grace rule for blood knots; Leeson relaying DuPont on tier variation, and the blood knot for leader building.
• Leader knots — Global FlyFisher (Steve Schweitzer) — the double ample for most tippet connections, the triple against slippage; the account of Jim Vincent's (RIO) 4X recommendation; friction heat weakening leader material.
• The Strongest Fishing Knots for Each Type of Line, Tested — Field and Stream (John Merwin) — blood knot 83%, 3-turn surgeon's 65%, Seaguar 66%, back-to-back unis printed 6% in fluorocarbon to mono; J knot 83%, 4-turn surgeon's 80%, back-to-back unis 75%, Seaguar 73% in braid to fluorocarbon; percentages against unknotted line strength.
• The Strongest Fishing Knots You Can Tie — Popular Science (Field and Stream syndication) — the same test, used to confirm the figures.
• Triple Surgeon vs. Blood Knot, Ep 662 — Tom Rowland — NexTech force tester, Orvis SuperStrong Plus 3X to 4X, blood knot 4.42 lb against triple surgeon's 2.52 lb on the retest.
• Blood Knot vs. Double Uni Knot Strength Contest — Salt Strong — six trials on 20 and 30 lb Ande mono; blood knot 13% stronger than the double uni.