The Hemostat Blood Knot, for unknown reasons is sometimes called the ORVIS Tippet Knot and was introduced by Lefty Kreh in Fly Fisherman Magazine around 2007. I don’t recall who Lefty credited.
The images were scanned from a booklet handed out at a Steve Kantner Presents seminar with Lefty Kreh in 2011
When the situation of dissimilar diameters or dissimilar materials (mono to fluorocarbon) comes up this knot, which in some circles is called the Seaguar Knot, is almost a 100% strength knot. It’s way more trustworthy than an actual Blood Knot and far, far easier to tie. Especially so in the “field” when your hands are cold and the river is raging or you are off shore and the boat is rocking.
See video on tying the Seaguar Knot . . .
You don’t need a hemostat to tie it . . .
. . . That, obviously indicating the knot was authored by a trouter. You can tie it using just fingers, or a pencil-like tool. Using fingers requires more practicing because more line is used – need to get those lengths correct.
NOTE: It is extremely important to get all the maneuvers completed exactly as shown. It may look simple, but it will take some time to master, practice until flawless.