Chain hanger-gadget

LarryJM wrote:

gmw photos wrote:

joshuajim wrote:
Consider this. The chains on my 10,800# Wildwood measure .333 inch. Thats less than a 3/8" chain. Probably is a Chinese manufacture chain of questionable quality and given FR's push on cost control is probably a grade 30 chain. That means that it might have a strength as low as 1900#. The chains bear no markings (43 or 70). To meet DOT requirements, each chain would have to be a full 3/8" grade 70 chain.

I think the chains the manufacturer installs are mostly cosmetic.

With all due respect, I don't think that is a correct statement.

A chain with a material dia of .333" is most likely 5/16" chain. That size of grade 30 chain would have a WLL of 1900 lbs., but a min breaking strength of 7600 lbs. The pair would have a combined strength of 15,200 lbs, which would meet DOT req for your 10,800 lb trailer.

Close, but I think you will find the DOT requirement is for EACH SAFETY CHAIN must have a breaking strength equal to or greater than the trailers GVWR. My post above went into these details along with the strength of the next grade up 5/16 chain.

Larry

Well Larry, close....but not quite. From the Federal Motor Carrier Safety Admin:

Question 2: When two safety chains are used, must the ultimate combined breaking strength of each chain be equal to the gross weight of the towed vehicle(s) or would the requirements be met if the combined breaking strength of the two chains is equal to the gross weight of the towed vehicle(s)?

Guidance: If the ultimate combined breaking strength of the two chains is equal to the gross weight of the towed vehicle(s), the requirements of §393.70(d) are satisfied. It should be noted that some States may have more stringent requirements for safety chains.

https://www.fmcsa.dot.gov/regulations/title49/section/393.70