---

Carbon
Iron		Balance
Manganese
Nickel
Silicon

Principal Design Features		This is one of the controlled expansion alloys. It has an expansion rate roughly 10 % that of standard carbon steels. Also known as Invar 36 or Alloy 36, the only alloy with lower CTE is Super Invar, or Alloy 32-6, but this alloy is extremely rare and is generally only produced by the mill in heat lot quantities. Note: Recent testing has determined that increased hardness will decrease CTE in all temperature ranges in Invar alloys.

Applications		Commonly employed in electronic equipment such as radios, laser systems and thermostats.

Machinability		This alloy can be machined employing most common methods. It is known to produce "gummy" chips and is best machined at slow speeds with positive and constant feeds.

Forming		The alloy is readily formed using most common practices and should not present any unusual problems. For maximum properties, material should be fully annealed after any forming operations.

Welding		All common joining techniques can be successfully employed here. When a filler metal is required, it is suggested to use a similar composition alloy, available from the manufacturer.

Forging		Heat to 2150 F(1180 C) rapidly and cool rapidly following working. Do not soak at temperature.

Cold Working		This alloy can be cold upset and swaged successfully.

Annealing		Hold at 1450 F(790 C) 30 minutes for every inch of thickness, followed by air cooling. To obtain maximum dimensional stability, soak at 1500 F(815 C) and water quench. Reheat to 600 F(315 C) for 1 hour and air cool.

Hardening		This alloy will not respond to hardening by thermal treatment.

Physical Data : [top]

Density (lb / cu. in.)	0.293
Specific Gravity	8.11
Specific Heat (Btu/lb/Deg F - [32-212 Deg F])	0.12
Electrical Resistivity (microhm-cm (at 68 Deg F))	495
Melting Point (Deg F)	2600
Modulus of Elasticity Tension	21

Form		Strip
Condition		Cold Rolled
Temper		70
Tensile Strength		105
Yield Strength		98
Elongation		6
Rockwell		B97
Form		Strip
Condition		Test Specimen Annealed
Temper		70
Tensile Strength		64
Yield Strength		39
Elongation		34
Reduction of Area		65
Rockwell		B69