SLING CONSIDERATIONS - D/d
WIRE ROPE SLINGS
When a wire rope sling is rigged as a basket, the diameter of the load can affect the sling’s lifting capacity. How much the lifting capacity is affected can be calculated by dividing the diameter of the load (represented by ‘‘D’’) by the diameter of the wire rope (represented by ‘‘d’’).
   D/d Ratio
Wire Rope Sling Strength E ciencies
25/1
100%
20/1
92%
15/1
88%
10/1
86%
8/1
84%
6/1
80%
4/1
75%
2/1
65%
1/1
50%
d
D
                             Example:
When the diameter of the load is 4 times the diameter of the wire rope sling the D/d ratio is 4/1 and the sling ef ciency is 75%.
D d
WEB SLINGS
Capacity reductions are not required when considering D/d ratios for synthetic web slings.
POLYESTER ROUNDSLINGS
When considering D/d ratios for roundslings, the manufacturer’s recommendations for the sling must be followed. Roundsling load  bers are of many different types and deniers. Different  ber types and component sizes react differently around pin diameters. Please contact us for further information.
= 2 ÷ .5 = 4
 2’’ load diameter (D)
4 1
1/2’’ wire rope diameter (d)
75% ef ciency
=
    Sharrow Lifting Products 97 (651) 489-1341 • (800) 565-8821