Sheathing, Lead-Covered Cable

A cable provided with a lead sheath for the purpose of ex­cluding moisture from the conductors and insulation. Also used as earth return. The sheath consists either of commercially pure lead or pure lead to which a small percentage of rarer metals has been added for hardening purposes. The extrusion of lead and its alloys in the screw type of continuous machine from time to time runs into difficulties, par­ticularly with the harder alloys. The lead sheath may be reinforced by metal tapes against internal pressure in pressurized cables.