So, how strong is a knot...Knot very!
According to the U.S. Coast Guard in their Boat Crew Seamanship Manual common knots loose much of the line's strength. The following table is from the above manual.
|Knots or Splice||Percent of Line
Breaking Strength Lost
|Percent of Line
Breaking Strength Remaining
|Two Bowlines (Eye in Eye)||43||57|
|Double Becket Bend||41||59|
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