Champion 504 Industrial Spark Plug N21 Copper Core

The Champion 504 (N21) Industrial Spark Plug is a heavy-duty ignition component designed for industrial and agricultural equipment operating in high-compression and aggressive environments. This non-resistor spark plug delivers reliable performance in demanding applications including generators, compressors, farm equipment, and stationary engines.

Key Features:

• Copper-cored nickel center electrode for superior conductivity and heat control
• Nickel alloy ground electrode with J-gap design for optimum ignitability
• Lower voltage requirement compared to precious metal plugs
• 14mm x 1.25mm thread diameter with gasket seat
• 19mm (3/4") reach for proper combustion chamber fit
• 21mm (13/16") hex size for easy installation and removal
• Removable nut terminal for flexible wire connections
• Standard projection, non-projected tip design

Installation Specifications:

• Torque for cast iron heads: 26-30 lb-ft
• Torque for aluminum heads: 18-22 lb-ft
• Gap spark plug to manufacturer's specification before installation

This spark plug is manufactured for long-lasting durability and backed by Champion's global engineering expertise from Federal-Mogul. The N21 is engineered to withstand high-temperature, high-load service environments common in industrial applications. Cross-references to NGK B5ES/BR5ES and Bosch W8CC spark plugs.