All sling angles as mentioned in this catalogue are measured from the horizontal.

As the angle decreases the stress imposed on the leg of a sling increases. A simple demonstration makes this very clear. Imagine one carries a weight with one’s arm hanging down, and then try lifting the same weight sideways up and away from your body. When computing sling capacities always take this most important factor into account. As can be seen from the table, sling stresses increase tremendously with angles smaller than 45°.

Only where headroom is a limiting factor should sling angles smaller than 30° be applied and careful computation made to ensure that a sling of proper size is used to provide safe working conditions.

Which Angle Applies?

One of the most frequently asked questions.
ALWAYS apply the HORIZONTAL sling angle. If you use slings of unequal length apply the SMALLEST sling angle.

Angularity Factor (AF)

Although the known trigonometrical functions apply to all stress calculations, many trade publications and standards give specific sling strength calculation examples which one can follow.

For a ‘day-to-day’ practical calculation we found the following method the easiest way to determine the sling size required.

 
 
Horizontal
Angle		 Angularity
Factor (AF)
90 1.000
85 1.003
80 1.015
75 1.035
70 1.064
65 1.103
60 1.154
55 1.220
50 1.305
45 1.414
40 1.555
35 1.743
30 2.000
(25) (2.366)
(20) (2.924)
(15) (3.863)
(10) (5.759)

Example:

A 5 ton load has to be lifted with 2 slings. The horizontal sling angle is 50°, the slings legs have equal length, and the center of gravity is in the center of the load (if not, see Centre of Gravity).

Solution to find required sling capacity (or WLL):

3.26 tons is the VERTICAL Rated Capacity required for EACH sling. Look up the tables in this catalogue and select the sling size required.

NOTE: Remember to apply additional reduction factors as required; e.g. Choker Hitch & D/d reduction factors.
(..) Angles below 30° should be avoided.