I'm not sure what the venders steering rods are made of but 1 1/2" bar should be over kill, I was talking about the elongation and yeild strength of the 440 being more like alloy steel.
4340 (chromoly) Normalized Alloy Steel
Minimum Properties Ultimate Tensile Strength, psi 186,000
Yield Strength, psi 125,000
Elongation 12.2%
Rockwell Hardness B100
303 stainless steel (cold drawn annealed, room temperature)
Minimum Properties Ultimate Tensile Strength, psi 89,900
Yield Strength, psi 34,800
Elongation 50%
Rockwell Hardness B83
440 Stainless Steel (annealed condition)
Minimum Properties Ultimate Tensile Strength, psi 110,000
Yield Strength, psi 65,000
Elongation 14%
Brinell Hardness 285 max
17-4 PH Stainless Steel Condition A (annealed)
Minimum Properties Ultimate Tensile Strength, psi 160,000
Yield Strength, psi 145,000
Elongation 5%
Rockwell Hardness C35