WLL stands for Working Load Limit and corresponds to the maximum authorized workload for each device. It is expressed in tons (t) or kilograms (kg).
A decanewton (daN) is a decimal multiple of the SI unit of the newton force. According to Newton's second law of motion, one newton is equal to the amount of force needed to accelerate a mass of one kilogram to a speed of one meter per second squared. Therefore, 1 N = 1 kg • m / s².
STF (Standard Tension Force) indicates the pre-tensioning force. It is the most important value to qualify a ratchet tensioner. It is expressed in daN.
The strength of the anchoring is detected through the LC (Lashing Capacity) anchoring capacity. It is expressed in daN.
Whether a load can slip (for example during braking) also depends on the contact surface between the load surface and the load itself. The greater the friction, the lower the LC value required. An anti-slip mat complies with a coefficient equal to or greater than 0.6 μ.
The safety factor varies according to the material from which a product is made and according to its use. For polyester hook lifting products it is 7: 1, for steel chains it is 4: 1 and for steel ropes it is 5: 1. For anchoring systems, where PES strips and steel components are joined, 3: 1 is calculated for textile parts and 2: 1 for steel accessories.
The Maximum Securing Load is the value of the maximum load that a fastening product can withstand before starting to deform plastically. The IMO (International Maritime Organization) considers 50% of the breaking force of the system as the MLS value.
After each use, each product should be cleaned and dried as needed. They should be stored in a temperate and dry place, away from UV rays and chemicals.
◉ Check before each use and in any case quarterly by the safety / maintenance manager of the company.
◉ Check that the WLL capacity of the sling is correct with the weight of the load to be lifted.
◉ Keep them in optimal conditions.
◉ Illegible or absent marking.
◉ There must be no signs of deformation, wear or corrosion.
◉ Exposing the sling to temperatures higher or lower than those indicated.