Chain Breaking Strength

Chain grades what does g30 g43 g70 g80 g100 and g120 mean.

Chain breaking strength.

Chain grades are a standard method for showing the ultimate breaking strength tensile strength of a chain. 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. Chain is graded based on the ultimate breaking strength of the chain measured in n mm 2 the american society of testing materials astm has published safety standards and regulations for these chain grades. It is unclear why the wll definition is different for grade 40 chain.

This number is what we see today g30 g43 g70 g80 g100 and the common chain grades. Grades help determine what sort of applications are appropriate for a given chain. Just as important as tensile strength is a chain s fatigue strength. With galvanized chain it basically boils down to how much carbon is in the steel.

When it comes to ratchet straps winch straps and just about any other type of strap in the cargo industry the words working load limit wll and breaking or break strength are commonly seen. Lower chain grades g30 and g43. How to determine a chain s working load limit. The wll wroking load for chain is usually defined of the ubs ultimate breaking strength expressed in pounds for all chain types except g4 grade 40 htchain has the wll defined as 1 3 of the ubs.

The wll of a chain is determined by both the grade and the diameter. Chain grades are determined by calculating newtons per square millimeter using the formula n mm 2. Toll free 866 392 2829 ph 918 392 2829 f 918 392 2833. The higher the grade the greater the break strength.

See chart for astm specification number. Chain is embossed with both the grade and size so you can determine. The most common measure of roller chain s strength is tensile strength. The critical factors in a chain s fatigue strength is the quality of steel used to.

Chains must be inspected regularly to make sure it is safe to use. Every piece of webbing buckle ratchet and end hardware has its own number associated with both its wll and break strength. Memorial dr 126 bixby ok 74008. Grade 43 aka grade 40 has higher tensile strength and abrasion resistance and comes with a higher price tag.

The wll is a quarter or a fifth of the chain s breaking strength. One of the safety measures implemented was to place chain in grades based on the ultimate breaking strength of that chain. What is break strength vs. Grade 30 aka proof coil has less carbon and is good service duty chain.

Tensile strength represents how much load a chain can withstand under a one time load before breaking.