UNS C63000 bronze
Specify wrought nickel-aluminum bronze by product standard, size and temper; qualify heat treatment, bearing duty and corrosion exposure separately.
Tags: materials, copper-alloys, bronze, bearings, heat-treatment
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Identify the grade and manufacturing route
Concast's AMS 4640 C63000 table for HR50 or TQ50 gives 50 ksi / 345 MPa minimum yield for a 4 in round in its over 3 through 5 in row. The 68 ksi / 470 MPa row ends at 1 in. Both measure 0.5% extension under load. Using the smaller-size value would overstate the minimum by 125 MPa, about 36%. Concast size and test table
UNS C63000 is a wrought nickel-aluminum bronze. Its name identifies a copper-alloy grade, rather than one finished-component strength or corrosion rating. Wieland Concast stocks an extruded and drawn AMS 4640-C63000 product, with HR50 drawn and stress relieved or TQ50 temper annealed conditions. Keep the manufacturing route and condition with the designation. Wieland Concast C63000 reference
Copper Alloys Ltd lists composition ranges of 9.0–11.0% aluminum, 4.0–5.5% nickel plus cobalt, 2.0–4.0% iron, with copper balance and limits for other elements. These ranges should remain ranges; a nominal description such as “10% aluminum, 5% nickel” is not a complete acceptance chemistry. The supplier's cross-reference includes CW307G and CuAl10Ni5Fe4, but substitution still requires checking the actual product standard, composition and properties. Copper Alloys Ltd C63000
Order manufacturer/grade, governing specification and revision, product form, dimensions, temper, surface condition and required certification. State whether the material is raw bar, a forging blank or a finished component. Do not replace C63000 with a cast nickel-aluminum bronze simply because the family name or application looks similar. National Bronze's heat-treatment reference separately identifies C63000 / AMS 4640, C63020 / AMS 4590, and cast grades such as C95510 / AMS 4880. National Bronze, November 19, 2019
Strength depends on size, form and test definition
Concast's table for HR50 or TQ50 rounds, hexagons and octagons, presented according to AMS 4640, gives:
| Size range | Tensile strength, minimum | Yield at 0.5% extension under load, minimum | Elongation in 4D, minimum |
|---|---|---|---|
| Up to 1 in inclusive | 110 ksi / 760 MPa | 68 ksi / 470 MPa | 10% |
| Over 1–2 in inclusive | 110 ksi / 760 MPa | 60 ksi / 415 MPa | 10% |
| Over 2–3 in inclusive | 105 ksi / 725 MPa | 55 ksi / 380 MPa | 10% |
| Over 3–5 in inclusive | 100 ksi / 690 MPa | 50 ksi / 345 MPa | 10% |
These entries are a named supplier's reference to a specific specification and product group. Confirm the applicable revision and required tests with the purchase order. A 0.5%-extension-under-load yield result is not automatically interchangeable with a 0.2%-offset proof-strength result. Concast mechanical-property table
Temper and heat treatment
Copper Alloys Ltd defines HR50 as drawn and stress relieved and TQ50 as quench hardened and temper annealed. Those conditions describe different routes to the required material state. A certificate or drawing should identify the required final condition rather than saying only “heat treated.” Copper Alloys Ltd temper definitions
National Bronze explains that stress relief addresses stresses from cold work, rapid cooling or machining, and can reduce movement when thin-walled bushings are machined. Its discussion distinguishes stress relieving from higher-temperature annealing and from quenching/tempering. Removal of substantial stock can still make dimensional stability a process concern; plan roughing, any authorized intermediate treatment and final machining together. National Bronze heat-treatment discussion
The Copper Development Association's Publication 222, revised December 2018, describes martensitic transformation on rapid cooling of nickel-aluminum bronzes and the subsequent effects of tempering. This is family-level metallurgy, not permission to apply one cycle to every C63000 section. Establish the required properties, qualified temperatures/time, section-dependent cooling and final inspection with the producer or heat treater. Guide to Nickel Aluminium Bronze, sections 4 and 7
Do not treat an annealing range, melting point or supplier high-temperature application statement as an allowable service temperature. A loaded component needs relevant strength, creep, relaxation or fatigue evidence at its actual temperature and duration. Welding or local heating also requires review of the resulting material condition.
Corrosion is exposure-specific
The CDA guide explains that nickel-aluminum bronze relies on a protective copper/aluminum-rich oxide film. It warns that sulfides in polluted or stagnant water can damage this protection and does not recommend the alloy family for sulfide-polluted conditions. Film formation, crevices, galvanic coupling, selective phase attack, flow and cavitation are separate considerations. Its discussion covers multiple wrought and cast grades; the reader must retain those distinctions. CDA guide, sections 6.1–6.11
A marine application listing therefore does not establish immunity to seawater corrosion or one universal flow limit. Define water chemistry, oxygenation, sulfides, temperature, stagnation, local velocity, deposits, mating metals and commissioning conditions. For a pump or valve, examine the actual local geometry and service cycle rather than assigning a family-wide corrosion allowance.
Likewise, chemical-service acceptance needs the named chemical, concentration, temperature and exposure duration. A favorable result in clean seawater cannot qualify an acid-cleaning process, polluted-water layup or a dissimilar-metal assembly. Specify the required evaluation and inspection for the component's pressure boundary or load-bearing function.
Bearing, machining and joining choices
Copper Alloys Ltd describes C63000 applications involving anti-galling performance against steels, including bearing bushes. This identifies candidate service, rather than a load-speed rating. Copper Alloys Ltd applications
A bearing design still needs mating-shaft material and hardness, finish, clearance, lubrication, pressure, sliding speed, alignment, temperature and contamination limits. “Wear resistant” does not mean self-lubricating, and a raw-material tensile result does not establish bearing life. Qualify the actual tribological pair and duty cycle.
Concast reports a machinability index of 30, while Copper Alloys Ltd reports 20 against free-machining brass at 100. Preserve the source rather than promising a universal percentage or deriving spindle speeds from either index. Concast product data, Copper Alloys Ltd machining index
Use a qualified tool/process trial to establish dimensions, surface finish and burr removal. For joining, obtain the intended filler, preparation, welding procedure and any subsequent treatment requirements. A catalog weldability rating does not establish the strength, corrosion behavior or inspection acceptance of a completed joint. Obtain the current supplier handling information for cutting, grinding and thermal processing.
Source versions and release
Sources were reviewed November 1, 2026. The three-page Concast PDF and Copper Alloys Ltd product page show no visible technical revision date. The CDA PDF explicitly states January 2016, revised December 2018; National Bronze's article is dated November 19, 2019. Hosting paths and crawl dates are not revisions.
Release against the ordered chemistry, form, size and final temper, with specified mechanical tests, dimensional/surface inspection and any required soundness checks. Keep lot and heat-treatment identity with the component. Distinguish supplier typical values, specification minima and demonstrated assembly performance.