Related Clues:

• Silver source
• Boxcar cargo, perhaps
• 50-Down member's find
• Lake Oswego st.
• TV chef lead-in
• Kettle metal
• Work (out), as differences
• Mined material
• Wood complement
• Elementary stuff
• See 29 Down
• Something to pump?
• Shipment to a steel mill
• Cores core?
• Tin source