Knot guide · Beginner
Grinner Knot (Uni Knot): How to Tie It
The grinner knot, known internationally as the uni knot, is the Swiss Army knife of fishing knots. It ties hooks, swivels and leads to almost any line, ties easily in the dark, handles heavy mono well, and doubled up as the double grinner it becomes one of the most reliable line to line joins in fishing.
Published by the GilledIt editorial team · Last reviewed 2026-08-19 · Part of the fishing knot library
Step by step
How to tie the grinner knot (uni knot)
- 1
Thread and double back
Thread the line through the eye and double it back so the tag end runs alongside the standing line.
- 2
Form the loop
Form a loop by laying the tag end back over the doubled section of line.
- 3
Wrap through the loop
Wrap the tag end through the loop and around the doubled line 4 to 6 times.
- 4
Snug and slide
Wet the knot and pull the tag end to snug the wraps together, then slide the finished knot down to the eye.
- 5
Trim
Trim the tag end and test the knot with a firm, steady pull.
Two rules apply to every knot: wet it with saliva before pulling it tight, because dry friction weakens mono and fluorocarbon at the exact point you need strength, and tighten slowly, then test with a firm pull before you cast.
Get it right
Common mistakes to avoid
Wrapping around the standing line but outside the loop. The tag must pass through the loop on every turn; miss it and you have tied a coil that unravels under the first proper load.
Sliding the knot down to the eye before the wraps are snugged. Snug the barrel of wraps first with a steady pull on the tag, then slide the finished knot down. Sliding a loose knot deforms the wraps and costs strength.
Using the same turn count on every line. Six turns that grip light braid will not seat in 18lb mono; four turns that seat in heavy mono will slip on braid. Match the turns to the line.
Jerking it tight dry. The grinner's barrel of wraps generates real friction as it closes, and dry friction burns mono and fluorocarbon exactly where the knot needs full strength.
Leaving the knot seated part-way down the line as an accidental loop. Fished deliberately that is a valid trick, but if you want a fixed knot, make sure it slides all the way to the eye and locks there.
How strong is it?
Retains around 90 to 95% of line strength. Exact figures vary with line type, diameter and how well the knot is tied, so treat any percentage as a guide, not a guarantee.
When to use the grinner knot (uni knot)
Hooks, swivels and leads on any line type, especially when you need a dependable knot tied by feel in the dark or in heavy mono. Tie two grinners facing each other on overlapping lines and you have the double grinner, a sensible alternative to the FG knot for joining braid to a leader.
Which lines does the grinner knot (uni knot) suit?
The grinner is the closest thing to a line-agnostic knot, but the turn count should follow the line. On light mono and braid, lean towards six wraps: thin, slippery lines need the extra friction. On heavy mono of 15lb and upwards, drop to four; more turns simply refuse to seat and the knot finishes as a loose stack. Fluorocarbon sits in the middle at five, wetted thoroughly because fluoro is the least forgiving line to seat dry. On braid some anglers double the line through the eye first for extra bite, which turns it into a double-loop grinner at very little cost in bulk.
The bigger picture
How does it compare?
Where the grinner knot (uni knot) sits among the ten knots in the library, by the line types it suits, how much strength it keeps, how bulky the finished knot is, and how hard it is to tie.
| Knot | Best for | Strength retention | Bulk | Difficulty |
|---|---|---|---|---|
| Palomar Knot | Mono, fluorocarbon and braid | ~95% | Compact | Beginner |
| Grinner Knot (Uni Knot)(this guide) | All line types | 90–95% | Moderate | Beginner |
| Improved Clinch Knot | Mono and fluorocarbon (not braid) | 90–95% | Slim | Beginner |
| Knotless Knot (Hair Rig) | Braided and coated hooklinks | ~90% | Slim (spread along the shank) | Beginner |
| FG Knot | Braid to fluorocarbon or mono leader | 90–95% (of the braid) | Very slim | Advanced |
| Figure-of-Eight Loop | Mono and fluorocarbon hooklengths | 80–85% | Moderate | Beginner |
| Snell Knot | Mono and fluorocarbon (braid also snells well) | ~95% or better | Slim (spread along the shank) | Intermediate |
| Albright Knot | Two lines of clearly different diameters | 80–90% | Moderate | Intermediate |
| Surgeon's Knot | Two lines of similar diameter | ~90% (more in triple form) | Bulky | Beginner |
| Arbor Knot | All line types (braid needs backing or tape) | n/a — grip matters, not strength | n/a (buried on the spool) | Beginner |
Grinner Knot (Uni Knot): common questions
Yes. Grinner is the traditional UK name and uni is the international one, but the knot is identical. Sea anglers in particular rate it because it ties easily in the dark and handles heavy monofilament well.
Two grinner knots tied facing each other on overlapping lines, then drawn together. It is one of the most reliable line to line joins in fishing and the best easier alternative to the FG knot for connecting braid to a fluorocarbon or mono leader while you learn the FG.
Four to six wraps through the loop is the standard range. Lean towards more turns on thin or slippery lines like light mono and braid, and fewer on thick, heavy mono where too many wraps stop the knot seating cleanly.
Both are excellent hook knots with similar strength. The palomar edges it for outright strength and simplicity, but it needs the whole hook or lure passed through a loop. The grinner avoids that, so it wins for big lures, trebles and hook patterns where the palomar is impractical.
Keep learning
Related knots
Palomar Knot
Any time you tie a hook, swivel or snap link to mono, fluorocarbon or braid. Its only real weakness is practical rather than structural: the whole hook or lure has to pass through the loop, which gets awkward with big lures and treble hooks.
Read the guideFG Knot
Joining braided mainline to a fluorocarbon or mono leader, especially in lure fishing where the join must pass through the rod rings on every cast. Practise it at home five or six times before you trust it on the bank; the double grinner is the fallback while you learn.
Read the guideSurgeon's Knot
Joining two lines of similar diameter quickly, attaching tippet to a fly leader, or building a paternoster link, especially mid session when speed matters. It is bulkier than a blood knot and sits slightly off axis, so it is not the join for repeated casting through small rings.
Read the guideFor all ten knots in one long read, see the fishing knots guide, or browse the full knot library. Ready to put it to work? The carp rig library shows what to tie next.
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