Rotation-Resistant 19x7

Wire Rope

In an application where a single-part hoist rope is used to lift a free load -- or where rotation-resistant properties are essential for rope performance -- the 19 x 7 can be used. Its rotation-resistant characteristic is achieved by laying six strands around a core strand in one direction, then laying 12 strands around the first operation in the opposite direction. Thus, when the rope is in tension, opposing rotational forces are created between the inner and outer layers.

In addition, frequent and regular inspection for broken wires is critical when using this rope. Due to its design, the 19 x 7 construction has a relatively low reserve strength. This can result in short service life between the point in time when the broken wire removal criteria are met and when actual rope failure occurs.

Diameter (in.) 8 x 25 XIP® 19 x 7 XIP® Flex-x® 19
Approx. wt./ft. (lbs.) Minimum Breaking Force (tons of 2000 lbs.)* Approx. wt./ft. (lbs.) Minimum Breaking Force (tons of 2000 lbs.)* Approx. wt./ft. (lbs.) Minimum Breaking Force (tons of 2000 lbs.)*
3/16 - - 0.064 1.57 - -
1/4 - - 0.133 2.77 - -
5/16 - - 0.177 43 0.18 4.63
3/8 0.31 83 0.25 6.15 0.26 6.63
7/16 0.4 11.2 0.35 8.33 0.36 8.97
1/2 0.54 14.6 0.45 10.8 0.47 11.6
9/16 0.69 18.5 0.58 13.6 0.6 14.7
5/8 0.85 22.7 0.71 16.8 0.73 18.1
3/4 1.25 32.4 1.02 24 1.06 25.9
7/8 1.68 43.8 1.39 32.5 1.44 35
1 2.17 56.9 1.82 42.2 1.88 45.5
11/8 2.75 71.5 23 53.1 2.39 57.3
11/4 3.45 87.9 2.83 65.1 2.94 70.5
13/8 4.33 106 3.43 78.4 3.56 84.9
11/2 5.11 125 4.08 92.8 4.24 100

Rotation-resistant ropes can frequently provide the best and most economical service in specific applications when you choose, handle and use them properly.

Contra-helically laid, rotation-resistant ropes are different from standard ropes because they're designed to reduce rope torque. Modes of failure and wear for rotation-resistant ropes can differ from those for standard rope constructions. The very nature of these ropes requires special handling, selection and usage not encountered with standard constructions. They are susceptible to kinking, crushing and unbalancing in the form of "core pops" and "birdcages". Use extreme care to avoid operational practices that can possibly lead to these conditions.

Rotation-resistant ropes should not be used with swivels that allow rope rotation -- or in single part lifts where the load can rotate. Rotation will cause a reduction in strength, unequal loading in the rope and possible rope unbalance. If any significant change in diameter is found in a short length of a rotation-resistant rope, the rope needs to be replaced.

These ropes should be replaced when you see two randomly distributed crown wire breaks in six rope diameters -- or four randomly distributed crown wire breaks in 30 rope diameters.

Because rotation-resistant ropes are special, there are separate design, maintenance, inspection and removal criteria established for them by applicable industry regulations and standards.

We recommend that rotation-resistant ropes be used with a minimum design factor of 5.0.

* These strengths apply only when a test is conducted with both ends fixed. When in use, the strengths of these ropes may be significantly reduced if one end is free to rotate