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List of Alloys & profiles

List of Alloys & profiles

Alloy Wire International

Datasheet: Ni-Span-C Alloy 902®

Ni-Span-C Alloy 902®

A precipitation hardenable Nickel-Iron-Chromium alloy having outstanding controllable thermoelastic coefficient characteristics and excellent oxidation resistance in high temperature atmospheres. The alloy can be processed to have a constant modulus of elasticity at temperatures ranging from -45 to +65°C (-50 to +150°F).

Available in all profile options

Ni-Span-C Alloy 902® - Alloy Wire International 1

Key Features

Ni-Span-C Alloy 902® offers the following key features:

Outstanding controllable thermoelastic coefficient characteristics.
Can be processed to have constant modulus of elasticity from from -45 to +65ºC (-50 to +150ºF).
Good for springs in watches and weighing equipment.
Age hardenable.

Typical Applications

Ni-Span-C Alloy 902® is known to be suitable for the following applications:

Springs in precise applications, such as watches and weighing machines


UNS N09902
AWS 080


AMS 5225
AMS 5221
HS 261

Chemical Composition

The chemical composition of Ni-Span-C Alloy 902® is indicated in the table below:

ElementMin %Max %
FeBal Bal

Alloy Details

Ni-Span-C Alloy 902® density, melting point, coefficient of expansion, modulus of rigidity, and elasticity is indicated in the table below:

DensityMelting PointCoefficient of ExpansionModulus of RigidityModulus of Elasticity
8.05 g/cm³1480 °C7.6 μm/m °C (20 – 100 °C)62 – 69 kN/mm²165 – 200 kN/mm²
0.291 lb/in³2700 °F4.2 x 10-6 in/in °F (70 – 212 °F)8993 – 10008 ksi23932 – 29008 ksi

Heat treatment of finished parts

The typical heat treatment of Ni-Span-C Alloy 902®:

Condition as supplied by AWITypeTemperatureTimeCooling
Spring Temper – For good all round propertiesAge Harden650 °C (1200 °F)2 HrAir
Spring Temper – For max stabilityStress Equalise
Age Harden
400 °C (750 °F)
650 °C (1200 °F)
2 Hr
2 Hr
Spring Temper – For minimum hysterisis & low thermoelastic coefficientStress Equalise400 °C (750 °F)2 HrAir


The typical mechanical properties of Ni-Span-C Alloy 902®:

Approx. tensile strength<800 N/mm²<116 ksi
Approx. operating temperature (for constant modulus applications)-45 to +65 °C-50 to +150 °F
Spring Tempered
Approx. tensile strength900 – 1100 N/mm²131 – 159 ksi
Approx. operating temperature (for constant modulus applications)-45 to +65 °C-50 to +150 °F
Spring Temper + Aged
Approx. tensile strength1300 – 1500 N/mm²189 – 218 ksi
Approx. operating temperature (for constant modulus applications)-45 to +65 °C-50 to +150 °F

The above tensile strength ranges are typical. If you require different please ask.

*Trade name of Special Metals Group