Nope - you can't. I don't think you can harden stainless, even though it's already hard. No way stainless is grade 8. When you need grade 8, you need grade 8!
17-4 Stainless is available and very comparable strength wise to typical grade 8, and far superior to typical grade 2 stainless fasteners.
Physical Properties:
Melting Point: 2560 - 2625°F (1404 – 1440°C)
Density: 0.282 lbs/in3 / 7.8 g/cm3
Modulus of Elasticity in Tension: 28.5 X 106 psi / 197 GPa
Mechanical Properties:
Condition: Solution Treated (A)
Tensile Strength Minimum (psi): 160,000
Yield Strength Minimum 0.2% offset (psi): 145,000
% Elongation in 2” Typical: 5%
Hardness: Rockwell B85
Condition: Hardened + Aged (TH1050)
Tensile Strength Typical (psi): 200,000
Yield Strength Typical 2% offset (psi): 185,000
% Elongation in 2": 8%
Hardness: Rockwell C35
Condition: Aged (H1075)
Tensile Strength Typical (psi): 175,000
Yield Strength Typical 2% offset (psi): 165,000
% Elongation in 2": 8%
Hardness: Rockwell C37
Condition: Aged (H900)
Tensile Strength Typical (psi): 210,000
Yield Strength Typical 2% offset (psi): 200,000
% Elongation in 2": 7%
Hardness: Rockwell C45
For reference sake, its likely double the cost of typical SS.
