Patent ID: 6603244
Filing Date: 2003-08-05
Classification: H01T

Abstract:
A spark plug comprising:a central electrode; an insulator surrounding the central electrode radially; a metallic shell surrounding the insulator radially; and a ground electrode having a first end connected to the metallic shell and a second end defining a side face, the ground electrode being so bent that the side face of the second end faces the central electrode, the ground electrode containing: a nickel in a range from 58% to 71% by weight, a chromium in a range from 21% to 25% by weight, an iron in a range from 7% to 20% by weight, and an aluminum in a range from 1% to 2% by weight, in which the ground electrode has a Vickers hardness in a range from Hv 140 to Hv 220 measured through a Vickers hardness test specified in Japanese Industrial Standard Z2244, a load 9.8 N being applied to the ground electrode in the Vickers hardness test.