Designed in the 1990-ies with the same design requirements as the QLK double-entry rope thread. This thread was not designed from scratch, but based on the existing AR tapered rope thread.
The main improvement of the 2R thread over the AR thread is the number of turns required to lock / unlock (3.5 turns). It was not stronger than the AR thread and not as easy to clean as the QLK thread.
Dimensions and Characteristics
Available (effective) lengths : 1,000, 500 and 300 mm
Outer diameter : 36 mm
Inner diameter : 16 mm
Weight : 6.5 kg/m
Length of the MALE thread : 39 mm
Outer thread diameter (top) : 22 mm
Outer thread diameter (base) : 31 mm
Required number of turns to lock / unlock : 3.5