Refining the uni knot

[Volitan]

I have been tying the uni knot for probably 30 years and for all that time I’ve wondered what is the optimum number of turns, or if it even matters. Today I decided it was time I answered the question.

The original 1944 specification for the knot was for 3 turns. I decided to start there but got slippage, so assume that back in 1944 lines were different then they are today. Then I tried 4, 5, 6 and 8 turns. I have heard people claiming as many as ten turns is ideal.

As you can see from the attached spreadsheet, the differences are not great. The optimum number of turns works out to be around 5 or 6. I doubt either of these results will surprise anyone.

Note that the result for 8 turns starts to get a bit erratic.

Using Penn Super X in 20 lbs (real tested breaking strain was 25.5lbs, the line is underrated by manufacturer).

For those who cant download:

3 turns – slippage occurred on 4 of 5 tests

4 turns – average = 23.4lbs

5 turns – average = 24.3lbs

6 turns – average = 24.4lbs

8 turns – average = 23.7lbs

 

While I was at it, I thought I’d try comparing the double loop uni to the single. I’ve heard people say that the single loop is actually a better knot because it provides almost the same strength without the slight unreliability that comes from drawing up a double loop.

Using 6 turns around the mainline, the results for were:

Double loop – average = 24.4lbs

Single loop – average = 20lbs

So wrong, not even close.

 

FYI, by double loop uni I mean two turns through the hook eye.

 

I also use the uni knot for braid, so one day soon I’ll test that too.

Optimising the uni knot.xlsx

[macca02]

Nice work! I've always tended to lean towards a locked half blood knot (not sure why, probably because it was the first knot I learnt) for terminal tackle.

I do however use Uni knot for heavier/thicker diameter leaders (40lb and up).

I find when I tie 60lb leaders (black magic tough leader) the more turns the harder it is to get the knot to cinch down and finish nicely. I normally max out at 4 turns.

I wonder if the same findings ring true as you go up in line sizes. E.g. maybe less turns would be better as the knot can lock down on itself.

 

[Volitan]

Yeah, I have always instinctively done less turns for heavier nylon. Never tested it though.

cheers

[Stino]

Good info to see someone testing and giving specs on the knots. Personally I double loop every uni knot on the eye of the hook-lure-swivel if the size of the line and eye allows. Other wise use an improved clinch knot, where the tail goes back through the loop before pulling down, this I find really reduces slippage especially on the big mono with fewer twists.

[kingie chaser]

So the experiment was with Penn superX mono. correct?

Ive always done 5 turns form mono, 7-8 for thinner braid.

 

Will be interested to see the braid results.

 

Thanks for sharing 👍

[Volitan]

Nope. Maybe I didn’t express myself well but the first set of 5 tests (ie 3,4,5,6 and 8 turns) was the DOUBLE LOOP.

Then I tested the SINGLE LOOP, but only for 6 turns around the mainline. The single loop broke at an average of 20lbs.

 

And just to be clear. By ‘turns’ I mean the number of times the tag end is wrapped around the mainline. By ‘loops’ I mean the number of times the line is passed through the eye of the hook.

cheers

 

[Volitan]

And yep,  Kingie Chaser, the line used was

Penn Super X nylon mono, 20 lb bs.

it actually breaks at 25.5lbs, being underrated by the manufacturer.

[Green Hornet]

Volitan, in all your testing have you noticed any consistency with the line failing in a particular place on the knot? 

[Volitan]

2 hours ago, Green Hornet said:

Volitan, in all your testing have you noticed any consistency with the line failing in a particular place on the knot? 

Yep. Most of the time the double loop uni will break at one of the two loops that go through the hook eye - like 90 or 95%. It’s easy to tell because you end up with a clean hook.

Occasionally the knot breaks at the other end, where the main line exits the wraps. I think these are inferior ties where the knot has not drawn up well and one turn is excessively tight. When this happens you get a little knot left on the hook which must be cut off.

[kingie chaser]

I never use a double look in my uni so by your findings it's a stronger knot then.

[Berleyguts]

2 turns through the eye?... I have enough trouble getting the line through there once!!! 😂😂😂