Principal Design Features		409 is an alloy designed principally for the automotive exhaust industry, although it has been used successfully in other industrial applications. It combines good elevated temperature corrosion resistance with medium strength, good formability and overall cost. In recent years, however, and with the upcoming US government requirement for a 100,00 mile exhaust capability, other alloys have been becoming more prevalent.

Applications		Automobile mufflers, catalytic converters, tailpipes, farm equipment, structural supports and hangers, transformer cases, diamond tread plate and shipping containers.

Machinability		Machining this alloy produces tough, draggy chips with heavy build-up. While this alloy can be machined in the annealed condition, it tends to perform better in the cold drawn or heat treated condition.

Forming		This alloy is quite ductile in the annealed condition and can be easily formed using all commonly employed practices. Experienced fabricators report that it is similar in formability to soft carbon steel.

Welding		Can be successfully welded employing SMA, GMA and GTA processes. When not used in a high temperature environment, filler metal AWS ER309 is acceptable for use. For stronger, more resilient welds at high temperature, use weld filler such as 409 Cb, AWS ER430 or W18 Cr-Cb.

Hot Working		Heat to 1500-1600 F(816-871 C) then rapidly heat to 1900-2050 F(1038-1121 C). Do not soak at this temperature and do not work at temperatures below 1500 F(816 C). Air cool forgings.

Cold Working		Despite a rather low work hardening rate, this alloy can be easily formed using most common methods.

Annealing		Soak material at 1200-1400 F(649-760 C) and air cool.

Hardening		This alloy is not hardenable by heat treatment.

Physical Data : [top]

Density (lb / cu. in.)	0.278
Specific Gravity	7.68
Specific Heat (Btu/lb/Deg F - [32-212 Deg F])	0.11
Modulus of Elasticity Tension	29

Form		Sheet
Condition		Test Specimen Annealed
Temper		70
Tensile Strength		68
Yield Strength		39
Elongation		30
Form		Sheet
Condition		Test Specimen Annealed
Temper		200
Tensile Strength		58
Yield Strength		28
Elongation		28
Form		Sheet
Condition		Test Specimen Annealed
Temper		400
Tensile Strength		53
Yield Strength		24
Elongation		21
Form		Sheet
Condition		Test Specimen Annealed
Temper		600
Tensile Strength		50
Yield Strength		22
Elongation		20
Form		Sheet
Condition		Test Specimen Annealed
Temper		800
Tensile Strength		46
Yield Strength		19
Elongation		22
Form		Sheet
Condition		Test Specimen Annealed
Temper		1000
Tensile Strength		36
Yield Strength		16
Elongation		28
Form		Sheet
Condition		Test Specimen Annealed
Temper		1200
Tensile Strength		23
Yield Strength		13
Elongation		34
Form		Sheet
Condition		Test Specimen Annealed
Temper		1300
Form		Sheet
Condition		Test Specimen Annealed
Temper		1400
Tensile Strength		8
Yield Strength		4
Elongation		68
Form		Sheet
Condition		Test Specimen Annealed
Temper		1500
Form		Sheet
Condition		Test Specimen Annealed
Temper		1600
Tensile Strength		4
Yield Strength		2
Elongation		79