Provincial
Well-known member
Anyone know the application for this USN NAF socket? 1/2" drive, cad finish, appears to be unused. Has an internal plastic ring similar to that used in some automotive spark plug sockets. Aircraft spark plug socket?
![]()
![]()
![]()
Shielded spark plug for aircraft have a threaded section on the upper end of the plug where the nut for the shielded harness attaches. A deep-broached socket will damage those threads if the socket is not perfectly centered. The plastic insert in this socket protects those threads.
Shielded aircraft spark plugs used several hex sizes for the plug and for the harness. At some point 7/8" hex was standardized for the plug base. Later two sizes were standardized for the harness nuts, 3/4" and 7/8" hex.
The hex size on this socket will tell you something about its age.





