Load Limit(WLL) & Min. Breaking Strength(M.B.S.):
learning how to use ratchet tie down straps, it’s important to
use a strap based on the Min. Breaking Strength (MBS) and
working load limit (WLL).
component of a ratchet strap assembly- the webbing, the ratchet,
and the end fittings- have a breaking strength that is
determined through independent testing. The breaking strength is
the amount of weight a component can withstand before failing.
tie down assembly is only as strong as its weakest point, the
component with the lowest breaking strength is considered the
breaking strength of the entire ratchet strap assembly.
working load limit is then determined based on the breaking
strength. The working load limit is figured by taking 1/3 of the
breaking strength of the weakest component. This means a tie
down strap with an assembly breaking strength of 10,000 lbs.
would have a working load limit of 3,333 lbs. An assembly should
never be used in applications over its working load limit.