Posted by C. Garbee on Tuesday, February 19, 2002 at 4:34PM :
In Reply to: Re: Aren't cable RH & LH depending on how they fit the winch posted by Bill Wincapaw on Monday, February 18, 2002 at 6:24PM :
Reproduced here from the Hanes Supply catalog with it's "wire rope 101" are a couple paragraphs from their page...
Obviously, they have a few more examples (seal construction for instance) and illustrations on their site (and it all is in PDF in case you want to print it out for future reference in the field...)
The “lays” of Wire Rope
"Lay" of a wire rope is simply a description of the way wires and strands
are placed during construction. Right lay and left lay refer to the direction
of strands. Right lay means that the strands pass from left to right across
the rope. Left lay means just the opposite: strands pass from right to left.
Regular lay and lang lay describe the way wires are placed within each
strand. Regular lay means that wires in the strands are laid opposite in
direction to the lay of the strands. Lang lay means that wires are laid in
the same direction as the lay of the strands.
Most of the wire rope used is right lay, regular lay. This specification has
the widest range of applications and meets the requirements of most
equipment. In fact, other lay specifications are considered exceptions and
must be requested when ordering.
Here are some exceptions:
Lang lay is recommended for many excavating, construction, and mining
applications, including draglines, hoist lines, dredgelines and other similar
lines. Here's why: Lang lay ropes are more flexible than regular lay ropes.
They also have greater wearing surface per wire than regular lay ropes.
Where properly recommended, installed and used, lang lay ropes can
be used to greater advantage than regular lay ropes. However, lang lay
ropes are more susceptible to the abuses of bending over small diame-ter
sheaves, pinching in undersize sheave grooves, crushing when wind-ing
on drums, and failing due to excessive rotation. Left lay rope has
greatest usage in oil fields on rod and tubing lines, blast hole rigs, and spud-ders
where rotation of right lay rope would loosen couplings. The rotation
of a left lay rope tightens a standard coupling.