The story of a Knot: the Duncan Loop – Uni Knot – Grinner

first published here on the 15th of November 2011 with the diagram above and great video tutorial, i was very pleased when Norman Duncan, the creator of this classic knot joined in on the comment section.
an even better surprised happened yesterday when Norman graciously sent in the story and evolution of his ‘Duncan Loop’ that was missing from the original link that i had found.

now, when talking about the ‘Duncan’, most anglers around the world will say that’s it’s just a Uni knot and in the UK it’s typically referred to as the ‘Grinner’.
they are indeed the same knot as explained here on
this all fits in well with Norman’s description and also explains that Dunaway’s invention was simply realising that the knot could be used other purposes than just tying on a fly…

Duncan (Uni) Knot Details

The Duncan Knot is named after its inventor Norman Duncan and is also known as the “Grinner Knot”. It was also popularized under the name Uni Knot by Vic Dunaway as a versatile knot which can be adapted to many purposes including snelling; joining two lines; and connecting hooks, swivels and lures with a loop. It is described as being the same as the Hangman’s Noose. Although the two knots are tied differently, the Duncan (Uni) undergoes a transformation as it is tightened. The outer wraps become internal and the resulting knot is the Hangman’s Noose.

for sure, the angling community can be quite grateful for Dunaway’s invention because the basic knot is outstanding and is as good as any other from the reel all the way to the fly (securing backing to the reel spool – backing to fly line – fly line to leader butt – joining leader materials – terminal end to the fly) but adapting the exact same thing, renaming it (even if Uni/Universal really fits the bill) and claiming it is pretty lame so, with the intention of giving credit where credit is due and of sharing a little piece of fishing history, here’s Norman’s story. enjoy !

In the early 1960’s I was trying to develop a new way of tying a nail knot between the fly line and the butt end of the leader, I wanted to eliminate the need for using a nail. Someone had started using a small tube instead of the nail to facilitate the tying of the nail knot which allowed you to start pulling down the knot with the coils of mono tighter than with a nail. Any method of tying a nail knot in a boat was difficult especially if the fish were hitting. Alternatively, I tried tying the nail knot with tension on the fly line so that it would function like a nail. Although it worked it was also difficult since it required three hands and two sets of pliers. Then I started tying an overhand knot with the mono around both the fly line and the mono leader, passing the end of the mono through the loop three to six times then pulling it down with tension on both the mono leader and the fly line. When the mono folded over and started snugging down I then slid the knot down to the end of the fly line and cinched it. This worked alright if you were in a hurry but the mono loops would usually pinch up some of the fly line coating in the process. I then tried the same technique on heavy mono in order to improve my methods. It was when I used these techniques to tie the nail knot back on the mono itself that I realized this created an entirely new knot that could have many different applications. I then started experimenting with different methods of tying this knot finally developing the following as the easiest:

First grasp the end of the line with your lead hand and pull it through the thumb and forefinger of the opposite hand toward then around the base of the little finger to form a loop. Hold the two lines lightly with the same thumb and forefinger pull the end out about 8 inches and circle around to create a 3 inch diameter loop with about 3 inches sticking out. Pass the tag end over the three lines and through the loop at least four times for mono over 100 pound test and successively more times with successively smaller line sizes. Pull the tag end and standing line together snug enough so that the knot will set and not loosen. Then put the loop on something smooth and solid like a small cleat or a gaff hook under foot. Grasp the tag end with pliers and the standing line with the other hand then apply equal tension on both lines in the same direction, pull slowly and hard to control the loop size until the knot folds over its self and snugs up to the desired tightness. The loop size can then be adjusted smaller by putting your pliers loosely against the top of the knot and pull the leader till it slips down. The tag end is cut off by pressing your cutters against the top of the knot between the leader and the tag end at about a 45 degree angle. When cut in this manner, the tag end will make a smooth slope from the leader to the knot and pass through the water without picking up as much grass or debris.

This knot has many possible applications; however it is limited by the low knot strength. In some types or brands of mono the knot strength may be as low as fifty percent depending on how well the knot is tied. If the leader strength is close to the line strength you may want to experiment with the intended application by testing as many of the various sizes, brands and number of turns combinations you expect to use. This can be accomplished by tying the knots then using a line testing machine or just weighing a bucket of water when each different knot combination breaks and recording the results. The best applications that I found for this knot are; it is the easiest knot to tie in very heavy mono, heavy mono or steelon tippet to the fly, loop on fly tippets, mono leader to live bait hooks or trolling lures, the knot can replace metal crimped sleeves.

I invented this knot around 1962 and first started showing it to my friends, then to the various fishing clubs, the sportfishing community in South Florida quickly caught on and started calling it “Duncan’s Loop”. Everyone knew I had invented this unique knot that applied to many of the terminal tackle innovations that were developing during this time period. This name became well established through the years eventually becoming known as the “Duncan Loop”. One day in the mid 1970’s Vic Dunaway the local outdoor writer called me and asked if I could explain and show him my knot, I went over to his house in Cutler Ridge sat on his back porch and explained how I developed the knot, showed him how to properly tie it and demonstrated numerous applications along with the pros and cons of each. I was very surprised when a few months later Vic published an article in a sportfishing magazine in which he claimed to have invented a new knot that he called the “Uni Knot”. I understand that he justifies this by claiming that he adapted the knot to other applications. I have never confronted him regarding what I consider as his stealing and renaming my knot because he acquires notoriety and makes money by publishing articles related to the “Uni-Knot”. Since none of the sportfishing publications have seen fit to publish any of my writings I must find some way to document the innovations that I have made in the sportfishing arena. In this case the outdoor writer published his article about what I had invented over ten years earlier; meanwhile, none of these writers have quoted or published anything that has given me proper credit for the innovations that I created.
Norman Duncan

you’ll find the original article and knot tutorial video published here on TLC by clicking the knot image at the top of the page.

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