Stone Creek(TM) - Nail Knot Tool Choose from these four options! Pin-on Retractor with Silver Knot Tool Pin-on Retractor with Gunmetal Knot Tool Clip-on Retractor with Silver Knot Tool Clip-on Retractor with Gunmetal Knot Tool Click Here For Instructions: Nail Knot Tool Instructions. Stone Creek Nail Knot Tool. One of the best knots for adding leader to your fly line or the line to your backing. This stainless steel knot tool makes tying a Nail Knot easy. Comes with instructions. Colors: Gunmetal or Silver.