US 11,749,971 B1
Metallic shell for spark plug and spark plug using the same
Takahiro Sanda, Nagoya (JP); Keita Sugihara, Nagoya (JP); Noriyasu Hasegawa, Nagoya (JP); and Yohei Kozakai, Nagoya (JP)
Assigned to NGK SPARK PLUG CO., LTD., Nagoya (JP)
Filed by NGK SPARK PLUG CO., LTD., Nagoya (JP)
Filed on Feb. 15, 2023, as Appl. No. 18/109,934.
Claims priority of application No. 2022-023445 (JP), filed on Feb. 18, 2022.
Int. Cl. H01T 13/06 (2006.01)
CPC H01T 13/06 (2013.01) 8 Claims
OG exemplary drawing
 
1. A metallic shell for a spark plug, the metallic shell comprising:
a tubular metallic shell body;
a metal plating layer provided on a surface of the metallic shell body; and
a chromium-containing chemical conversion coating layer provided to cover the metal plating layer, wherein the chemical conversion coating layer has a zirconium component content of 0.1 mass % or more.