Stainless Steel - Grade 409 (UNS S40900)

Grade 409 steels are also available in highly stabilized forms, such as grades S40930, S40920 and S40910. The stability of these grades is provided by the presence of niobium, titanium, or both, in the composition of steels.

Key Properties

The properties given below relate to annealed tubing of ASTM A268. The specified properties may not be similar to other products such as bar and coil.

Composition

The typical chemical compositional ranges of grade 409 stainless steels are given below:

Table 1 - Composition ranges of grade 409 stainless steels

Grade		C	Mn	Si	P	S	Cr	Ni	Ti
409	min. max.	- 0.08	- 1.00	- 1.00	- 0.045	- 0.045	10.5 11.75	- 0.5	6x C 0.75

Mechanical Properties

The table below provides the mechanical properties of grade 409 stainless steels:

Table 2 - Mechanical properties of grade 409 stainless steels

Grade	Tensile Strength (MPa) min	Yield Strength 0.2% Proof (MPa) min	Elongation (% in 50mm) min	Hardness
				Rockwell B (HR B) max	Brinell (HB) max
409	450	240	25	75	131

Physical Properties

The physical properties of annealed grade 409 stainless steels are tabulated below:

Table 3 - Physical properties of annealed grade 409 stainless steels

Grade	Density (kg/m3)	Elastic Modulus (GPa)	Mean Coefficient of Thermal Expansion (μm/m/°C)			Thermal Conductivity (W/m.K)		Specific Heat 0-100°C (J/kg.K)	Electrical Resistivity (nΩ.m)
			0-100°C	0-315°C	0-538°C	at 100°C	at 500°C
409	7800	200	11.0	11.7	12.4	25.8	27.5	460	600