The fittings with the small-diameter threads are 1/4"-28 thread, same as 1/4" UNF or SAE bolts. The bigger ones have a tapered thread, 1/8" NPT pipe threads. Most of the fittings found on tie rods, ball joints, etc. are 1/4-28 and install with a 5/16" hex wrench or socket.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!