Is Amsteel the same thing as Amsteel Blue? They are not the same thing, but are often confused. As an example, the average strength of 1/4” Amsteel is 7400 pounds, while Amsteel Blue is 8600 pounds. Samson’s Amsteel is made from Dyneema SK60. Amsteel Blue is made from Dyneema SK75. What is being sold by cottage vendors today is usually Amsteel Blue, even if they don’t always call it that. Does Amsteel Blue have 8 strands or 12 strands? It depends. The 7/64 commonly used for whoopie slings, has only eight strands, but diameters beyond that have twelve. The Samson documentation invariably lists Amsteel Blue as a (class 2)12-strand product, but that documentation often does not include the 7/64 size because it is too small for the marine and industrial use that Samson caters to. Class I ropes are manufactured from polyolefin, nylon and or polyester fiber. Class II ropes (including Amsteel) are manufactured from high-modulus fiber, such as Dyneema.
(Paraphrased from a February 19, 2016 Blog written by Gravity on the Dutchwaregear website)