WORKING LOAD LIMITS: The maximum load (in pounds) which should never be applied
to chain, even when the chain is new and the load is uniformly applied in direct tension to a
straight, untwisted length of chain. The term “working load limit” contains no implication
of what load the chain will withstand if any of the above factors are changed.
Any chain can be subject to wear, twisting, misuse, overloading, intentional alteration and
corrosion. These and other usage variables may cause a reduction in their working load
limits. It is, therefore, important to regularly inspect all products to determine that they are
safe for continued use.
PROOF TEST: The load (in pounds) to which the chain was subjected, in the as-manufactured condition prior to the
time it left the factory. Under this test, a load has been applied in direct tension to a straight length of chain with a
uniform rate of speed on a standard chain testing machine. The sole purpose of this test is to discover defects in the
material or manufacturing process.
Every foot of Proof Coil (Grade 30), High Test (Grade 43) and Transport (Grade 70) chains are proof tested. Where
attachments such as hooks or rings are desired for use with chain in sustaining loads, care should be taken to select
the attachments of the type, grade and size compatible with the chain with which the attachments are intended to
GENERAL WARNING: Low and high carbon steel, weldless and welded chain, and accessories made from assorted
metals are intended to be used in tension or pull applications and are not to be used for lifting or hoisting purposes or
when their failure is likely to cause damage to property or persons. Jerking or acceleration in the rate of application
of a load multiplies the stress on the chain very rapidly and should be avoided.