347/347H(1.4550) Physical Properties

The physical properties of Types 321 and 347 are quite similar and, for all practical purposes, may be considered to be the same. The values given in the table may be used to apply to both steels.

When properly annealed, the Alloys 321 and 347 stainless steel tubing consist principally of austenite and carbides of titanium or columbium. Small amounts of ferrite may or may not be present in the microstructure. Small amounts of sigma phase may form during long time exposure in the 1000°F to 1500°F (593°C to 816°C) temperature range.

The stabilized Alloys 321 and 347 stainless steel pipe are not hardenable by heat treatment.

The overall heat transfer coefficient of metals is determined by factors in addition to thermal conductivity of the metal. In most cases, film coefficients, scaling, and surface conditions are such that not more than 10 to 15% more surface area is required for stainless steels than for other metals having higher thermal conductivity. The ability of stainless steels to maintain clean surfaces often allows better heat transfer than other metals having higher thermal conductivity.

Magnetic Permeability
The stabilized Alloys 321 and 347 are generally non-magnetic in the annealed condition with magnetic permeability values typically less than 1.02 at 200H. Permeability values may vary with composition and will increase with cold work. Permeability of welds containing ferrite will be higher.

Typical Physical Properties
Density
Alloy	g/cm3	lb/in3
321	7.92	0.286
347	7.96	0.288

Modulus of Elasticity in Tension
28 x 106 psi
193 GPa
Mean Coefficient of Linear Thermal Expansion
Temperature Range
°C	°F	cm/cm °C	in/in °F
20-100	68 - 212	16.6 x 10-6	9.2 x 10-6
20 - 600	68 - 1112	18.9 x 10-6	10.5 x 10-6
20 - 1000	68 - 1832	20.5 x 10-6	11.4 x 10-6
Thermal Conductivity
Temperature Range
°C	°F	W/m•K	Btu•in/hr•ft2•°F
20-100	68 - 212	16.3	112.5
20 - 500	68 - 932	21.4	14.7
Specific Heat
Temperature Range
°C	°F	J/kg K	Btu/lb•°F
0-100	32 - 212	500	0.12

Electrical Resistivity
Temperature Range
°C	°F	microhm•cm
20	68	72
100	213	78
200	392	86
400	752	100
600	1112	111
800	1472	121
900	1652	126

Melting Range
°C	°F
1398 - 1446	2550 - 2635

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347 Stainless Steel Tube | 347H Stainless Steel Pipe
304 | 304L | 304H| 316/316L| 317L| 321/321H | 309S | 310S | 347/347H| S32205/S31803| S32750