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Bosch HR6DC (Sold as Each)

is a discontinued copper core spark plug that was part of the Super series. It is primarily associated with certain Volvo 6-cylinder and Mercedes engines, though some new old stock (NOS) may still be found like here in this store.

Specifications

Key specifications for the Bosch HR6DC plug include:

Center Electrode: Heavy-duty yttrium-enhanced copper core.
Ground Electrode: Taper-cut nickel chromium.
Seat Type: Tapered.
Thread Reach: 17.5mm (0.689").
Heat Range: 6.
Thread Size: 14mm.
Hex Size: 5/8".
Features: Nickel-plated threads for anti-seize and corrosion protection, and a metal-glass fused resistor for interference suppression.