AISI Type S21904 (Alloy 21-6-9) Stainless Steel, 30% final cold reduction, stress relieving heat treatment 705C (1300F) for 2 hours, air cooled

Subcategory: Ferrous Metal; Heat Resisting; Metal; Stainless Steel; T S20000 Series Stainless Steel

Close Analogs: AISI Type S21900

Key Words: UNS S21904, AMS 5595, AMS 5656, ASME SA412, ASTM A269 (XM-11), ASTM A276 (XM-11), ASTM A314 (XM-11), ASTM A412 (XM-11), ASTM A473 (XM-11), ASTM A580 (XM-11)

Component   Wt. %
CMax 0.04 
Component   Wt. %
N 0.23 
Component   Wt. %
PMax 0.06 
SMax 0.03 
SiMax 1 

Material Notes:
Austenitic, high strength, excellent corrosion resistance, and low magnetic permeability. Applications include aircraft applications such as ducting and bellows systems, tail pipes and exhaust systems, clamps, fasteners, flanges, and hydraulic tubing.

Physical PropertiesMetricEnglishComments
Density7.83 g/cc0.283 lb/in 

Mechanical Properties
Hardness, Brinell290290 Converted from Rockwell C hardness.
Hardness, Knoop311311 Converted from Rockwell C hardness.
Hardness, Rockwell C3030 
Hardness, Vickers301301 Converted from Rockwell C hardness.
Tensile Strength, Ultimate1095 MPa159000 psi 
Tensile Strength, Yield965 MPa140000 psi at 0.2% offset
Elongation at Break40 %40 % in 50 mm
Modulus of Elasticity200 GPa29000 ksi Typical for stainless steel
Machinability30 %30 % Based on 100% machinability for AISI 1212 steel.

Electrical Properties
Electrical Resistivity7.3e-005 ohm-cm7.3e-005 ohm-cm 

Thermal Properties
CTE, linear 20C16.7 m/m-C9.28 in/in-F at 25-95C, 17.3 m/mC at 25-205C. Annealed
CTE, linear 250C18.2 m/m-C10.1 in/in-F at 25-315C. Annealed
CTE, linear 500C19.1 m/m-C10.6 in/in-F at 25-540C, 20.0 m/m-C at 25-760C, 20.0 m/m-C at 25-870C, 20.5 m/m-C at 25-980C. Annealed
Specific Heat Capacity0.48 J/g-C0.115 BTU/lb-F Typical value for stainless steel.
Thermal Conductivity13.8 W/m-K95.8 BTU-in/hr-ft-F 13.8 at 95C, 7.8 W/mC at -180C, 10.9 W/mC at -73C, 16.1 W/mC at 205C, 18.2 W/mC at 315C, 20.2 W/mC at 425C, 22.5 W/mC at 540C, 24.7 W/mC at 650C, 26.8 W/mC at 760C, 28.9 W/mC at 870C

References for this datasheet.

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