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Aluminum		0.9 - 1.35
Carbon		0.05 max
Chromium		12.25 - 13.25
Iron		Balance
Manganese		0.2 max
Molybdenum		2 - 2.5
Nickel		7.5 - 8.5
Nitrogen		0.01 max
Phosphorus		0.01 max
Silicon		0.1 max
Sulphur		0.008 max

Principal Design Features		13-8 MO is a precipitation, age hardenable stainless steel. It's principal features are high transverse toughness, good resistance to general and stress corrosion cracking, and high strength that is developed by a single low temperature heat treatment.

Applications		This alloy has been used in aircraft components such as landing gear and structural sections, valves, shafts, and components in the petrochemical and nuclear industries.

Machinability		This is a tough machining stainless steel. Although it can be machined in all conditions, best results can be obtained in condition H1150M. Compared to type 304 stainless, speeds should be roughly 25 % lower for optimum tool life and finish.

Forming		This alloy can be formed using conventional techniques with the degree of formability being limited only by its high initial yield strength.

Welding		Best welded in the solution annealed condition, using 13-8 MO filler material. Both resistance and inert gas shielded methods are acceptable.

Heat Treatment		CONDITION A--Soak at 1700 F (927 C) and cool below 60 F (16 C) for 1 hour. CONDITION RH 950- Treat Condition A material at -100 F(-73C) for 2 hours, air warm to room temperature (within 24 hours of solution treatment). Then heat cold treated material to 950 F(510 C) for 4 hours and air cool. CONDITION H950, H1000, H1050, H1100, H1150- Soak solution treated material for 4 hours at specified temperature, air cool, CONDITION H1150M- Soak solution treated material at 1400 F (760 C) for 2 hours, air cool, then re-heat to 1150 F (620 C) for 4 hours and air cool.

Forging		Soak at 2150 F(1177 C) for 1 hour prior to forging. Do not work below 1750 F(954 C). All forgings should be solution treated prior to final hardening. Air cool to room temperature after forging.

Hot Working		13-8 can be satisfactorily hot worked. Hot worked material must be solution annealed prior to hardening for reliable results.

Cold Working		Despite its high initial yield strength, this alloy can be satisfactorily cold worked.

Physical Data : [top]

Density (lb / cu. in.)	0.28
Specific Gravity	7.76
Specific Heat (Btu/lb/Deg F - [32-212 Deg F])	0.11
Electrical Resistivity (microhm-cm (at 68 Deg F))	613
Modulus of Elasticity Tension	28.3

MSO currently has no data available for this grade.