How to Make an Underwriter’s Knot

The photo clearly shows an underwriter’s knot before it is pulled tight. Note that the wire end that started on the left passes behind the cord before running through the loop on the right. The wire end that started on the right passes in front of the cord before running through the loop on the left. It doesn’t matter which wire end passes on the front or back of the cord; it only matters that one goes in front and one goes behind. This ensures the knot will be symmetrical and will tighten into a compact knot. Here are the basic steps for making an underwriter’s knot: Once the knot is complete, you can prepare the cord for the final connections by trimming each wire end to length and stripping 3/4 inch of insulation from the end, using wire strippers. It’s also possible to trim and strip the wires before making the knot, but for beginners, it’s more foolproof to leave the wire ends long and trimming them after making the knot.

Origin of the Underwriter’s Knot

The underwriter’s knot is similar to a basic form of the “wall knot” described in Ashley’s Book of Knots, a book that was originally published in 1944 and remains the definitive guide for making knots of all kinds. The term underwriter’s knot is generally believed to have come into use because this method was approved by insurance underwriters as a safer means for making electrical connections.