AMS 4598-C72900

Manufacturer of Custom Machined Parts

Cast 4598-C72900

Hardiall® (C72900) is produced by Lebronze Alloys. Hardiall is an extruded and drawn, spinodal hardened copper nickel-tin (CuNiSn) bronze alloy designed for high-strength applications where toughness is required. It resists mechanical wear, galling, stress relaxation, corrosion and erosion. It is non-magnetic and easy to machine into complex components. In addition, it is environmentally friendly, being lead and beryllium free, thus making it a beryllium copper substitute alloy.

Hardiall is used in aircrafts in various components thanks to its outstanding physical and mechanical properties, matching the stringent needs of the aircraft and aerospace industries. Because of these same characteristics, C729 is in high demand for the oil and gas industry, and others as well. C729 is also available, standard stocked, in AMS 4596 and AMS 4597 specifications.


PRODUCT DESCRIPTION: Copper Nickel-Tin Bronze
TEMPERS: TX 00 Solution Annealed and Spinodal Hardened
SOLIDS: 4.50" to 8.56" (114.30 mm to 217.42 mm) O.D.*

*Consult mill for other shapes/sizes

Typical Uses

AEROSPACE: brakes, compression fit airframe fasteners, control surface and actuator bushings and bearings, door hardware, electronic system connectors, helicopter controls, hydraulic actuators, landing gear bushings and bearings, steering joints, valves, wheel bearings, wing flap bearings
ELECTRICAL: connectors, contacts, controls, miniaturized sockets, relay elements, switches
INDUSTRIAL: springs, wire
MARINE: marine components
OIL AND GAS: bearings, bushings, drilling components, sucker rod, valve guide bushing couplings

Chemical Composition

Ni + Co%Sn%Fe%Zn%Mn%Cb%Mg%Pb%Cu%

Chemical Composition according to AMS 4598

Note: Copper + Sum of Named Elements, 99.5% min. Single values represent maximums.


Copper Alloy UNS No.Machinability RatingDensity (lb / in³)Density (gm / cm³)
AMS 4598-C729000.3238.94

Mechanical Properties

Mechanical Properties according to AMS 4598.

TX 00 Solution Annealed and Spinodal Hardened
Size Range: 1.10" (28mm) to 7.25" (184mm) Inclusive Nominal Outside Diameter (Tube); Forward Extruded

Ultimate Tensile Strength, minYield Strength, at 0.2% Offset, minElongation, in 4D, minRockwell "C" HardnessRemarks
ksiMPaksiMPa%min HRC

Size Range: 4.250" to 8.500" (108 to 216mm)) Inclusive (Nominal Thickness Between Parallel Sides) Bars, Rods

Ultimate Tensile Strength, minYield Strength, at 0.2% Offset, minElongation, in 4D, minRockwell "C" HardnessRemarks
ksiMPaksiMPa%min HRC

Physical Properties

 US CustomaryMetric
Melting Point - Liquidus2039 °F 1115 °C
Melting Point - Solidus1742 °F 950 °C
Density0.323 lb/in³ at 68 °F 8.94 gm/cm³ at 20 °C
Specific Gravity8.948.94
Electrical Conductivity7.8% IACS at 68 °F 0.045 MegaSiemens/cm at 20 °C
Thermal Conductivity17 Btu/sq ft/ft hr/°F at 68 °F 29.4 W/m at 20 °C
Coefficient of Thermal Expansion 68-5729.1 · 10-6 per °F (68-572 °F)15.8 · 10-6 per °C (20-300 °C)
Specific Heat Capacity0.09 Btu/lb/°F at 68 °F377.1 J/kg at 20 °C
Modulus of Elastic in Tension18500 ksi127554 MPa
Modulus of Rigidity7500 ksi51711 MPa

Fabrication Properties

Oxyacetylene WeldingGood
Gas Shielded Arc WeldingExcellent
Coated Metal Arc WeldingExcellent
Spot WeldExcellent
Seam WeldExcellent
Butt WeldExcellent
Capacity for Being Cold WorkedExcellent
Capacity for Being Hot FormedGood

Thermal Properties

TreatmentMinimum *Maximum *
Hot Treatment12001600

* Temperature is measured in Fahrenheit

Ready for a Quote?

Randall Bearings has a team of experts ready to assist you in selecting the proper materials and manufacturing your custom part.

Scroll to Top