Dyneema SK75 rope

riginal Dyneema winch rope from DSM. Stronger and much lighter than steel cables of the same thickness.

Breaking strengths per diameter:

6 mm: MBL 3.7 Ton - 36.3 kN

8 mm: MBL 6.0 Ton - 58.9 kN

10 mm: MBL 10.0 Ton - 102 kN

12 mm: MBL 14.0 Ton - 137 kN

16 mm: 24 ton

Please note: If a hook is spliced into it, the breaking strength is reduced by 10%.

Dyneema ropes also have some disadvantages. The melting temperature of Dyneema is around 165 degrees Celsius, and it begins to soften between 125 and 130 degrees. If a Dyneema rope rubs against something, the frictional heat will cause the rope to wear and break quickly. Also, the rope must not make bends with a radius shorter than 10 times its own diameter to prevent internal breakage.

Reading these specifications, it appears that the commonly sold hawse fairlead is completely wrong; a functioning roller fairlead creates less friction, and the radius of a roller is larger than that of a hawse fairlead.

First use: Dyneema ropes are braided from 12 different strands which are not all set to the exact same length during braiding. The strands need to "settle." You do this by attaching the rope to a tree, lightly engaging the car's handbrake (first click), and spooling the rope back onto the winch under light tension. Repeat this three times, each time applying the handbrake more firmly, so that eventually all strands are properly settled and can jointly absorb the forces. If you were to immediately apply a full load to a new rope, there is a chance that the strands that have not yet settled will break, causing the total breaking strength of the rope to decrease rapidly.