Dongqi Electric hoist safety tips on how to calculate the safety working load of you hoisting wire rope and hoist chains. Dongqi Hoist and Crane offers types of electric hoists, hoisting wire ropes and hoist chains to meet all you needs. Get your ideal hoisting wire rope and hoist chains, and electric hoist now.
Hoisting wire rope and hoist chains for sale from supplier
Hoisting wire rope and hoist chains are the important part of the hoist which are closely bound up with the safe work load, now let’s talk about the formula or rule of thumb to calculate the SWL of ropes and hoist chains.
All diameters are measured in millimeters (mm).
All weight are calculated in Kilograms(kg).
Diameter in mm squared=The weight in kg.
(Diameter)²=SWL Kg
Example: For a 12mm diameter rope.....
SWL=12*12=144Kg
Choosing the correct rope for the load
Fiber Rope Square root of weight
Example:900Kg load
Rope diameter=√90=30mm
6*19 (6 strands*19 wires)
6*24 (6 strands*24 wires)
6*37 (6 strands*37 wires)
Electric hoisting wire rope drawing
SWL=8D²
8 times stronger than Fiber
(Diameter)²*8=SWL Kg
Example: For a steel Hoisting wire rope of 15mm diameter
SWL=15*15*8=1800Kg
Square root of the load divide by 8
Example:5000kg load
Ø=√5000÷8
=√625
The diameter of steel Hoisting wire rope=25mm
SWL=8D²
10% of the wires broken in a length of eight times the diameter
Example:6*19 construction 20mm Diameter
6*19=114 wires
10% of 114 wires=11
8*20mm=160mm
11 wires broken over a length of 160mm discard sling
Electric hoisting wire rope drawing
Nine times stronger than Fibre
(Diameter)²*9=SWL (Kg)
Contoh: Garispusat=18mm
SWL=18*18*9
=2916Kg
SWL=9D²
Grade 30 hoist chains=9 times stronger than fiber rope
Grade 40 hoist chains=12 times stronger than fiber rope
Grade 60 hoist chains=18 times stronger than fiber rope
Grade 80 hoist chains=24 times stronger than fiber rope
0.3*diameter²MM*Grade of Hoist chains
Or SWL=0.3*D²*Grade
Square root of the weight (Kg) divide by the grade of China
Example: Weight=5400Kg & Grade=40
Diameter of Hoist chains=√Weight÷(0.3*Grade)
=√5400÷(0.3*40)
=21.2 mm
W=12D²
Load factor 2 slings at an angle
Sling angle 30° 60° 90°
Load factor 1.93 1.73 1.41
Full Wrap
Hoisting wire rope safe working load drawing
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Electric hoist safety tips on how to calculate the safety working load of you hoisting wire rope and hoist chains. Dongqi Hoist and Crane offers types of electric hoists, hoisting wire ropes and hoist chains to meet all you needs. Contact us to get your ideal hoisting wire rope and hoist chains, electric hoist, and Types of cranes now.
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