AMS 4598-C72900 Hardiall®

Reference guide

✔ Standard-stocked product

Extruded and drawn

Concast is the exclusive North American supplier of Hardiall® (C72900) 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. MORE»

Concast is also certified to AS9100 standards and requirements. AS9100 certificate can be viewed here.

*Lebronze alloys

AMS 4598-C72900 Hardiall®

Product description: Copper nickel-tin bronze
Tempers: TX 00 solution annealed and spinodal hardened
Tubes: 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.


AMS Machinability rating Density (lb/in3) Density (g/cm3)
AMS 4598-C72900   0.323 8.94

Mechanical properties

Mechanical properties according to AMS 4598

TX 00 Solution Annealed and Spinodal Hardened

Size range: 1.10" (28 mm) to 7.25" (184 mm) inclusive nominal outside diameter (tube); forward extruded
Ultimate tensile strength, min Yield strength, at 0.2% Offset, min Elongation, in 4D, min Rockwell "C" hardness Remarks
ksi MPa ksi MPa % min HRC
131 903 104 717 8 30
Size range: 7.25" (184 mm) to 13.6" (330 mm) inclusive nominal outside diameter (tube); back extruded
Ultimate tensile strength, min Yield strength, at 0.2% Offset, min Elongation, in 4D, min Rockwell "C" hardness Remarks
ksi MPa ksi MPa % min HRC
130 896 108 745 5 30

Physical properties

Physical properties provided by CDA

  US Customary Metric
Melting point - liquidus 2039 °F 1115 °C
Melting point - solidus 1742 °F 950 °C
Density 0.323 lb/in3 at 68 °F 8.94 gm/cm3 at 20 °C
Specific gravity 8.94 8.94
Electrical conductivity 7.8% IACS at 68 °F 0.045 MegaSiemens/cm at 20 °C
Thermal conductivity 17 Btu/sq ft/ft hr/°F at 68 °F 29.4 W/m at 20 °C
Coefficient of thermal expansion 68-572 9.1 ·10-6 per °F (68-572 °F) 15.8 ·10-6 per °C (20-300 °C)
Specific heat capacity 0.09 Btu/lb/°F at 68 °F 377.1 J/kg at 20 °C
Modulus of elasticity in tension 18500 ksi 127554 MPa
Modulus of rigidity 7500 ksi 51711 MPa

Fabrication properties

Fabrication properties provided by CDA
Technique Suitability
Soldering Excellent
Brazing Excellent
Oxyacetylene welding Good
Gas shielded arc welding Excellent
Coated metal arc welding Excellent
Spot weld Excellent
Seam weld Excellent
Butt weld Excellent
Capacity for being cold worked Excellent
Capacity for being hot formed Good

Thermal properties

Thermal properties provided by CDA
*Temperature is measured in Fahrenheit.
Treatment Minimum* Maximum*
Annealing 1515  
Hot treatment 1200 1600

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