John Cutler
Steel AJs are fairly easy to form with jigs but getting the angles right and fitting can be difficult.
I have been experimenting with Vincent de Bode’s version of the AJ, his AAJ, for some time (see MRJ123). He successfully uses 8 thou steel guitar string instead of 11 thou for the standard AJ. The advantages are that it needs a shorter shank and is marginally less visible. I have only suffered one breakage and that was on a 180 degree bend. Murphy’s Law says it is on the Hornby Adams Radial which is a real pig to fit an AJ hook onto! Vincent experimented with phosphor bronze wire but was unhappy with it. If you are thinking of adopting AJs, I recommend checking out MRJ123.
I will probably persevere with 8 thou steel wire for the Imprecise coupling hook and am still puzzled why Iain Rice chose phosphor-bronze. I wonder if it had anything to do with magnets? PB might be easier to form but conversely it will deform more easily!