Each Liftall material handling web
sling is installed with a load limit tag. The
tag may be leather 
or
a durable synthetic 
material. Working
load limits and a serial number will be legibly printed
onto the tag. Woven within the material is
a red code warring yarns which become visible when
a sling is damaged or otherwise ready for replacement.
Basically, there are two styles of material
handling web yarn; the flat yellow nylon or polyester
and the rounded color coded Tuflex polyester, treated
and untreated. In addition Liftall now offers the Keyflex Aramid Roundslings. A new roundsling that has higher working load limits, is lighter and very high heat ratings. Generally, a treated nylon web
can increase the damage resistance and degradation
of yarn integrity by environmental water contact. The
stretch capacities of synthetic web slings usually
are determined by the style of web yarn employed
during fabrication. Specialized towing straps
are available as a standard stocking item. Understanding
the lifting, choker or basket capacities of web style
slings are fairly straight forward. The levels
of strength that any web sling can provide are determined
by two factors; the number of ply's and the width
of web material used. Example: a one ply x
one inch wide web sling will have less capacity then
a two ply x two inch wide sling. Tables for
working load limits have long been established by
the various manufacturers. Remember, the working
load limit should be considered over the actual breaking
strength. Many manufacturers now only publish
the working load limit tables.
Angles have a negative effect on a web slings
working load limit. As the angle from vertical
increases, the working load limit degreases. Use
this chart 
to
estimate the degree of degradation to the sling. First
determine the degree of angle from vertical. Then
find the percent of degradation on the chart. Multiply
it by the slings working load limit. If the
net amount is less than the weight being lifted,
a stronger sling must be used.
Material Handling Synthetic Web Slings are now employed
over the traditional wire rope assembly. Synthetic
web assemblies are now used for overhead lifting
applications, truck tie down, towing and crane deployments. They
are generally lighter to carry and takes less space
for storage. Many times a web slings may be
more economical to use and have greater capacity
than a cable sling for the same job.
to
estimate the degree of degradation to the sling.