There are a TON of different types of Dyneema line out there but what makes them different from each other and what are the best uses of each? Dyneema in sailing is not too knew especially in sailboat racing but it may be considered new in it’s popularity in cruising and other genres of sailing, not to mention many other professional and recreational industries in the world. When I was first starting to learn about dyneema and it’s uses I began to realize that there are many different types and brand names of dyneema and started to become confused and overwhelmed about their characteristics and uses. I also couldn’t find a single source that explained all the different types of dyneema and what each was good for.
Before we get started, Dyneema is just a trade name for Ultra-High molecular weight polyethylene or “UHMWPE” fiber. Spectra is the other popular name for the same UHMWPE fiber. In the U.S. in sailing Dyneema is the term that is more widely used.
The dyneema fiber can be woven into an infinite variety of different strands and braids but before we even get there we have to understand that it can first be manipulated on the molecular level for different characteristics. These characteristics can pretty much be summed up into weight (aka specific density), strength, stretch, creep, UV resistance and chafe resistance.
Some of the popular types of dyneema are sk-75, sk-78, sk-90, sk-99, DM20, and Dux. These different types of dyneema are then woven into ropes which can be single braid or double braid, any number of strands (12 strand is the most popular in single braid), dyed, coated, impregnated and even blended with different types of fiber to form a blended rope. Once a rope is created it is then branded into what we see the name to be online and in stores. Some popular single braid dyneema product names are amsteel blue, HTS-99, HTS-78, DynIce 78, DynIce 99, DynIce Dux, etc. Some popular double braid dyneema core product names are Warpseed II, Endura Braid, D2, ect. Luckily, within the description or even in the product name itself we can determine exactly what type of Dyneema makes up the rope.
So, what are the most popular types of dyneema and what are their advantages and disadvantages? For this simplified discussion let’s stick to talking single braid dyneema, as double braid dyneema is just a single braid dyneema core with an added cover and whatever characteristics that cover brings with it. The standard single braid dyneema has been sk-75 for a long time and is a very versatile rope with great strength and low-stretch properties. This rope is being replaced with sk-78 which has similar strength to sk-75 but less “creep” (or permanent elongation on the molecular level). From here, sk-90 was another improvement but sk-99 quickly followed making sk-90 almost obsolete. Sk-99 has increased strength properties with similar stretch and creep properties as its predecessors but at a high financial cost. Dux is another very popular dyneema rope which is sk-75 that has been stretched under high load and heat to take all of the constructional stretch out of the rope. Dux is being used where minimal stretch and creep are necessary as in standing rigging. We even replaced all our standing rigging with 9mm Dux. New England ropes also has HRS-75 which is another heat-set sk-75 dyneema. DM-20 is a form of dyneema with virtually no creep but at a cost of strength with breaking strength being less than comparable ropes.
To sum all this up we can probably say that sk-75 or sk-78 is a great versatile rope to have and use all around a cruising boat where high strength is needed as well as low stretch compared to conventional ropes. If you need premium performance and have the budget then sk-99 might be the type of dyneema you are looking for and if stretch and creep needs to be as low as possible as in standing rigging you may consider looking at Dux, HRS, or DM20.
This article is meant to be a relatively simple explanation of the different types of dyneema and as I am writing it I am finding more and more variations, blends, and types of dyneema along with the advantages and disadvantages of each.
Below is a table to try to help organize and clarify different types of UHMWPE ropes, their trade names, product names, manufacturers, and characteristics. Please leave a comment below if you have anything to add.
