The Chain Rule.  In calculus, the chain rule is a formula for computing the derivative of the composition of two or more functions.  This extremely functional 2.3 cable chain is composed of 14/20 yellow gold filled wire. You don’t have to be a math genius to know you have a winning equation with this bulk jewelry chain. Add a clasp and jump rings to create a finished necklace. Check out our gold-filled chain and findings section to find everything you’ll need and more! Note: Bulk chain is priced per inch. All chains are sold in 12 inch minimum quantities unless a 10 foot minimum is noted. We may use segments of 7 inches or longer to fulfill your order if continuous lengths are not available. Spooled lengths are segmented at the factory so we cannot guarantee continuous lengths of any specific measure.