So grade 80 is really 800 and grade 120 is 1 200.
Chain working load limit.
The term working load limit wll refers to the maximum amount of tension that can be applied to a new and undamaged chain.
Working load limit wll of a chain is another designated safety measure.
Usa roller chain and sprockets is one of the nation s largest suppliers of roller chain and industrial pt components.
Working load limit wll is the maximum working load designed by the manufacturer.
A winch strap with a wll of 5 000 pounds should not be used to secure any load above that weight.
Do not put an unequal load on one leg of a sling.
Do not use a chain that appears to be defective worn or damaged.
Distribute the load evenly.
A chain s wll is the maximum tension that can be placed on an undamaged or brand new chain.
It is a rated capacity and often referred to in pounds.
Do not load an assembly in excess of working load limits shown.
It is always essential to know the working load limit of the chain you are using.
The working load limit of the chain must be sufficiently strong to support the load s weight as well as any added forces from the hitch types and angles used.
Do not tie knots or allow chains to become twisted.
The proof test load usually twice the working load limit is the load which the product withstood without deformation when new and under laboratory test conditions.
Determining chain working load limits.
An example of this would be a chain that has a mbl of 2000 lbf 8 89 kn would have a swl or wll of 400 lbf 1 78 kn if a safety factor of 5 5 1 5 to 1 or 1 5 is used.
Chains have a working load limit or wll of approximately one third of their break strengths the amount of force the chains can withstand before they break.
Working load limit is always 1 3 of the breaking strength.
The roller chain size charts below will help ensure you purchase the chain that suits your machinery best and provides the strength or load carrying capacity required by your specific manufacturing process.
Therefore a strap with a breaking strength of 15 000 pounds will have a working load limit of 5 000 pounds.
Wll mbl sf.
Table working load limits wll for chain chain size in millimeters inches unmarked chain grade 30 proof coil grade 43 high test grade 70 transport grade 80 alloy grade 100 alloy chain marking none 3 30 300 4 43 430 7 70 700 8 80 800 10 100 1000 7mm 1 4in 580kg 1 300lb 580kg 1 300lb 1 180kg.
Working load limits of chain whether you transport machinery use tow chains or are in the logging industry it s important to know the working load limits of chain you are using.
Do not expose assembly to impact rapid lifts or sudden stops.
