FUEL INJECTOR WITH INTERNAL RADIAL SEAL WITH THIN WALL COUNTERBORE

A fuel injector body (300) includes an at least partially annular configuration defining a longitudinal axis (306), a circumferential direction (308), and a radial direction (310). A first counterbore (314) and a first cavity (314a) extend from the first end (312) toward the second end (312a), and an external interface portion (334) includes a sealing surface (335) disposed axially between the first end (312) and a shoulder (336). The first cavity (314a) defines a bottom surface (330) and a peripheral surface (338) defining a first cavity diameter (316a), and the sealing surface (335) defines a sealing surface diameter (340). A ratio of the sealing surface diameter (340) to the first cavity diameter (316a) ranges from 0.3 to 4.4.