Possible Clues:

• Product of the Bessemer process
• Source of J.P. Morgan's fortune
• Former political leader is less than 100% iron
• Prepare route for fish to follow
• It's associated with some magnets and magnates
• Knife-sharpener
• This sort of iron may make one feel the pinch, perhaps
• Many a shipment to Detroit
• With 4-Down, Atlantic City attraction
• Douglas Reeman's Exterminator