Ni-Span C902: Complete Properties & Application Guide

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Overview

Ni-Span C902 (UNS N09902) is a nickel-iron-chromium alloy with a constant elastic modulus over a wide temperature range (-50°C to +80°C). The alloy is precipitation-hardenable through titanium and aluminum additions, making it ideal for precision springs and resonators.

Chemical Composition

The chemical composition of Ni-Span C902 is carefully controlled to achieve its unique combination of properties and performance characteristics.

Element	Min %	Max %
Nickel (Ni)	41.0	43.5
Iron (Fe)	Balance	Balance
Chromium (Cr)	4.90	5.40
Titanium (Ti)	2.20	2.60
Aluminum (Al)	0.30	0.60
Carbon (C)	—	0.06
Manganese (Mn)	—	0.80
Silicon (Si)	—	1.00

Mechanical Properties at Room Temperature

The mechanical properties of Ni-Span C902 vary depending on product form and heat treatment condition. The data below represents typical values for solution-annealed material.

Property	Value
Tensile Strength	1240 MPa
Yield Strength (0.2% offset)	965 MPa
Elongation in 2 inches	15%
Density	8.07 g/cm3
Melting Point	1380 °C
Max Service Temperature	450 °C

Corrosion Resistance

Good resistance to atmospheric corrosion. The chromium content provides moderate resistance to oxidizing environments. For severely corrosive environments, protective coatings may be required.

Applications

The unique combination of properties makes Ni-Span C902 suitable for a wide range of demanding applications:

• Precision Springs: Springs for watches, instruments, and timing mechanisms.
• Electronics: Tuning forks, resonators, and delay lines.
• Aerospace: Flexible couplings and precision instrument components.
• Telecommunications: Vibrating reeds and frequency control devices.
• Instrumentation: Bourdon tubes, diaphragms, and pressure-sensing elements.

Available Product Forms

Hangbo Alloy Group manufactures and supplies Ni-Span C902 in the following product forms, conforming to ASTM, AMS, and ASME specifications:

• Round Bars: Diameters from 6 mm to 300 mm, hot-finished or cold-drawn, solution annealed.
• Seamless Tubes & Pipes: Sizes from 6 mm OD to 219 mm OD, various wall thicknesses.
• Plates & Sheets: Thicknesses from 0.5 mm to 50 mm, hot-rolled or cold-rolled.
• Forgings: Custom flanges, rings, discs, and complex shapes per customer drawing.
• Welding Wire: Diameters 0.8 mm to 5.0 mm, precision-wound coils and spools.

Related Standards

Standard	Description
ASTM B478	Thermostat Metals
AMS 5221	Strip
AMS 5225	Wire
ASTM F30	Controlled Expansion Alloy
DIN 17745	German Standard
SAE AMS 5221	Aerospace Material

Contact Us for Ni-Span C902

Hangbo Alloy Group maintains extensive inventory of Ni-Span C902 in all standard product forms. We can provide mill test certificates, third-party inspection reports (SGS, TUV), and custom processing services.

For quotations, material certifications, or technical consultation, contact our sales team or call +86-136-1165-6360. We typically respond within 10 minutes.