"Billet" is simply a buzzword for "solid steel". The ones in the ad have been machined and swaged with the proper taper for the drag link, and the splines for the sector shaft. Any weld that carries the full load of the steering is pretty risky, such as cutting a Pitman arm into two pieces and welding in an extension.
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!