Lead to that of primary lead; some refining processes may be skipped depending on the material recycled and its potential contamination. Of the sources of lead for recycling, lead–acid batteries are the most important; lead pipe, sheet, and cable sheathing are also significant. Contrary to popular belief, pencil leads in wooden pencils have never been made from lead. When the pencil originated as a wrapped graphite writing tool, the particular type of graphite used was named "plumbago" (literally, "act for lead" or "lead mockup"). Lead metal has several useful mechanical properties, including high density, low melting point, ductility, and relative inertness.
Lead styphnate Lead styphnate Lead styphnate (lead 2,4,6-trinitroresorcinate, CHNOPb ), whose name is derived from styphnic acid, is an explosive used as a component in primer and detonator mixtures for less sensitive secondary explosives. Lead styphnate is only slightly soluble in water and methanol Samples of lead styphnate vary in color from yellow to gold, orange, reddish-brown, to brown. Lead styphnate is known in various polymorphs, hydrates, and basic salts. Normal lead styphnate monohydrate, monobasic lead styphnate, tribasic lead styphnate dihydrate, and pentabasic lead styphnate dehydrate as well as α, β polymorphs of lead styphnate exist. Two forms of lead styphnate are