Perfection Chain Products 30501 #18 Single Jack Chain, Stainless Steel Clean, 10 FT Bag The wire diameter of this chain is #18. The wire diameter of chain is the thickness of the wire used in each individual chain link Manufactured from steel wire for strength and durability This is a clean finished product, meaning excess flecks of material and grease have been removed The working load limit of this chain is 5 lbs. The working load limit of chain is the maximum load or weight that be held by the chain Made in the USA