Chain Strength Formula

[kramarczyk]

Originally Posted by Temper Metal

I have a chain and need to know how strong it is. I just don't know how to check without loading 100+pounds onto it. For those with a machinary handbook the W is .735 in., the L is .668 in., The P is1.322 in.
I do not know wwhere to begin with this problem. I tried several handbooks and none of them had the right size. Anyone that knows anything of help please let me know. I can use the formula myself if you just don't have time to solve it. I am hoping that the FIRST community can help me as this is a big project for me.

Based upon your description, assuming it is actually a standard ANSI roller chain, it sounds like a #100 (1.25" pitch, .75" wide, link plates thickness of .156"). That's a bit beefy for a bot. If this assumption is true then the following exerpt from the Machinery Handbook (26th Ed, p2424) applies:

Minimum Ultimate Tensile Strength: For single-strand chain, equal to or greater than 12,500 × (pitch in inches)2 pounds. The minimum tensile strength or breaking strength of a multiple-strand chain is equal to that of a single-strand chain multiplied by the number of strands. Minimum ultimate tensile strength is indicative only of the tensile strength quality of the chain, not the maximum load that can be applied.

Soooooo..... 19.5 kip per strand
yowza

'course Dave's test is the only way to know for sure.

Mark