Copper-Nickel-Tin
Hardiall® · UNS C72900, C72700 · spinodal Cu-Ni-Sn
Copper-nickel-tin alloys carry high loads in bushings, bearings and spring contacts, without beryllium or lead.
Alloy family
What this family is good at
Hardened by spinodal decomposition, free of beryllium
These alloys are hardened by spinodal decomposition, a heat treatment that strengthens the metal from within. Their hardness and elasticity compete with those of beryllium copper, with no beryllium or lead in the grade. Hardiall®, Niclafor® 1000 and Declafor are non-magnetic.
Hardiall® answers two constraints we hear from customers, beryllium exposure and import dependence. Wear resistance stays, and beryllium leaves the workshop and the supply chain.
Bearing surfaces that run with little lubrication
Hardiall® resists wear, galling, stress relaxation, corrosion and erosion, and its mechanical behaviour stays stable at elevated and sub-zero temperatures. It keeps running reliably when lubrication is limited. That is why it goes into landing gear and flight control bushings and bearings, valve guides and thrust washers, wellhead controls and drilling components, and gear drives.
Spring contacts and connectors in strip, wire and rod
Niclafor® 1000 combines very high strength, fatigue resistance and low friction with the elasticity that connector makers need. It is used in connectors, relays and test probes, as well as automotive bushings and eyewear parts. Declafor adds tellurium for easier machining and polishing, in spring contacts, coaxial connectors and watch parts.
The grades and how they are supplied
Hardiall®, CuNi15Sn8 (UNS C72900), is supplied in bars and tubes, compliant with AMS 4596, AMS 4597, AMS 4598, ASTM B929 and NACE MR0175. Hardiall Eco® and Niclafor® 1000 share the CuNi9Sn6 chemistry (UNS C72700), the first in bars compliant with ASTM B929, the second in rods, strips and wires compliant with ASTM B740. Declafor, CuNi7.5Sn5Te (UNS C72670), comes in rods and strips, and Niclal® 725, CuNi9Sn2, in strips compliant with CW351H.
Depending on temper, Hardiall® bars are guaranteed at a minimum tensile strength of 760 to 1,103 MPa, with a hardness of 240 to 314 HB.
Hardness and elasticity that compete with beryllium copper, from spinodal decomposition, without beryllium or lead.
Stable mechanical behaviour at elevated and sub-zero temperatures, and reliable running with limited lubrication.
Five grades in bars, tubes, rods, strips and wires, from landing gear bushings to spring contacts.
Range at a glance
The extent of this family's measured properties across its active variants — a range, never a single figure.
150 – 1,250 MPa
92/96 measured
380 – 1,300 MPa
94/96 measured
0 – 40 %
92/96 measured
277 HB
1/96 measured
8 – 13 %IACS
92/96 measured
8.9 – 8.94 g/cm³
96/96 measured
38 – 55 W/m·K
96/96 measured
All Copper-Nickel-Tin references
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Family highlights
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Used in
- Aerospace
- automotive
- Defence
- Electronics & Connectors
- industry
- Luxury
- oil-gas
- Energy & Nuclear
Specify it with an engineer
Replacing beryllium copper on an existing part
Send us the drawing, the current grade and the operating conditions. Our engineers recommend the closest copper-nickel-tin grade and temper, along with the tests to perform before making the switch.