60/40 Solder for Stained Glass is a 99.99% high purity alloy that is composed of 60% tin and 40% lead (no recycled metals). Nathan Trotter is alloyed in a proprietary method that results in a high wetting solder. Our 60/40 solder wire is an ultra-smooth flowing solder and is the best-selling alloy in the stained-glass field. It melts at 188 deg. C and solidifies at 183 deg. C. The "pasty range" of 60/40 is smaller than that of 50/50, giving the user a smoother bead. ⚠ WARNING: This product can expose you to chemicals including Lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.