Chemical Composition

Grade Symbol	UNS Number	Alloy	Elements	Composition %
F11 Class 2	K11572	1.25% chromium, 0.5% molybdenum	Carbon	0.10 - 0.20
			Manganese	0.30 - 0.80
			Phosphorus	0.040 max
			Sulfur	0.040 max
			Silicon	0.50 - 1.00
			Chromium	1.00 - 1.50
			Molybdenum	0.44 - 0.65

Mechanical Properties

Property	Value
Tensile Strength, min, ksi [MPa]	70 [485]
Yield Strength, min, ksi [MPa]	40 [275]
Elongation in 2 in. [50mm] or 4D, min, %	20
Reduction or Area, min, %	30
Brinell Hardness Number, HBW	143-207

Heat Treatment

After hot working, forgings shall be cooled to a temperature below 1000 °F [538 °C] prior to heat treating in accordance with the requirements.