Surgeon's Knots can be used for different types of materials and one of the most common things this knot is used for is fishing line. It is used most often for fishing for two reasons, first, it is an easy knot to remember and tie. Secondly, the Surgeons Knot is strong and estimated to be up to 100 percent strength as if it were a continuous line. This is a knot that can be used to join different materials whether equal or unequal in diameter but with the strength as if it was one piece without separate ends. 

There is also a Triple Surgeons Knot, which works on the same principle as a plain Surgeon's Knot. The way this type of single knot is tied is by making two overhand knots and pulling the entire leader through the knot each time. The Triple Surgeon's Knot is done by wrapping three times through the loop of the overhand knot. This kind of knot because it is a triple can be large because of the number of lines. the excess after the knot is tied can be trimmed. 

To ensure the knot is tied properly and is 100 percent strong and the way it becomes this way is after the knot is tied it must be tightened. The knot is tightened by pulling on all four strands or if doing a triple all the strands. This will seat the knot and then the excess after the knot is seated can be trimmed.

 

 

Then the lines are held in so there will be a loop to begin tying the knot. 

The line end and entire leader are passed through the loop two times. 

 Add moisture to the knot and then pull all four ends to set the knot.

 

 

This knot both ends and the leader line go through the loop one additional time. Then the ends are pulled to set the knot. Once, this kind of knot is set the knot will not come apart if done correctly. Even when used for fishing to reel in large fish, but if the knot is not done correctly or the ends cut before it is set the knot may come lose.