# UNS C95400 bronze

Specify cast aluminum bronze by casting standard, delivered condition and acceptance tests; distinguish C95400 and heat-treated product data from finished bearing or structural capability.

Reviewed: 2026-11-01

Tags: materials, bronze, copper-alloys, c95400, aluminum-bronze

## Identity, casting route and condition

Concast's **ASTM B505/B505M-23 continuous-cast** table lists **32 ksi / 221 MPa minimum yield** for **standard C95400** and **45 ksi / 310 MPa** for **C95400HT**. Both use **0.5% extension under load**, with elongation over **2 in or 50 mm**. Confirm the heat-treated condition and required test reports on the order. [Concast standard product](https://www.concast.com/files/C95400.pdf), [Concast heat-treated product](https://www.concast.com/files/C95400HT.pdf)

**UNS C95400 is a cast aluminum bronze**, also described as aluminum bronze 9C. Concast's continuous-cast sheet lists **Cu minimum 83%, Al 10.00–11.50%, Fe 3.00–5.00%, Ni maximum 1.50% including cobalt, and Mn maximum 0.50%**. Copper plus named elements must total at least **99.5%**. Retain the cited product-standard basis instead of treating this as the composition of every aluminum bronze. [Concast C95400 chemistry, ASTM B505/B505M-23 basis](https://www.concast.com/files/C95400.pdf)

Aviva identifies C95400 offerings under continuous-cast **ASTM B505** and centrifugal-cast **ASTM B271** specifications. This illustrates why an alloy name and a manufacturing specification answer different questions. Confirm which route and requirements belong to the quotation rather than assuming one stock description covers all processes. [Aviva C95400 product](https://www.avivametals.com/collections/bronze-alloys/aluminum-bronze/c95400-aluminum-bronze-9c)

## Standard scope and procurement requirements

ASTM **B505/B505M-23** covers continuously cast rod, bar, tube and shapes, including material supplied from stock with heat traceability. Its public abstract states that mechanical tests are required when specified by the purchaser. Put required test reports on the purchase order; do not assume that quoting a catalog minimum means every delivered piece was tensile-tested. [ASTM B505/B505M scope and abstract](https://store.astm.org/b0505_b0505m-23.html)

Agree traceability, sampling, test locations, dimensional inspection and any nondestructive examination appropriate to the part. Specify soundness and repair restrictions where they matter. The needs of a pressure-retaining body, thin machined sleeve and wear plate can differ even when all start with C95400 stock.

Keep the unit system consistent with the governing specification. ASTM treats its SI and inch-pound systems independently; paired supplier numbers need not be exact conversions. Define the acceptance basis rather than applying whichever rounded number is easier to pass. [ASTM units statement](https://store.astm.org/b0505_b0505m-23.html)

## Mechanical values: keep the conditions separate

Concast publishes these minimums for its **B505/B505M-23-based** products:

| Supplier product | Tensile strength | Yield at 0.5% extension under load | Elongation in 2 in. or 50 mm |
| --- | --- | --- | --- |
| C95400 standard product | 85 ksi / 586 MPa | 32 ksi / 221 MPa | 12% |
| C95400HT, heat treated | 95 ksi / 655 MPa | 45 ksi / 310 MPa | 10% |

The heat-treated entry belongs to the separately identified product. Its sheet does not supply a complete furnace recipe or authorize transferring its results to arbitrary shop-treated stock. [Concast C95400 table](https://www.concast.com/files/C95400.pdf), [Concast C95400HT table](https://www.concast.com/files/C95400HT.pdf)

Do not relabel the yield method as 0.2% proof stress. Preserve specimen gauge length and distinguish minimum tensile requirements from typical hardness or design allowables. For heat-treated material, require the condition, process and certification needed by the governing specification. Reassess dimensions and acceptance after machining or thermal processing.

## Wear and bearing applications need a system design

Aviva lists bearings, gears, valve components, wear plates and wear strips among typical applications. These examples identify possible uses rather than a universal operating envelope. [Aviva application guidance](https://www.avivametals.com/collections/bronze-alloys/aluminum-bronze/c95400-aluminum-bronze-9c)

For a bearing or guide, define mating material and hardness, alignment, clearance, surface condition, lubricant delivery, contamination, load, speed and duty cycle. Include startup, stopping, shock and loss-of-lubrication conditions. Obtain a justified pressure/velocity and temperature basis for the actual assembly instead of deriving one from tensile strength.

The Copper Development Association's sleeve-bearing guidance emphasizes reliable full-film lubrication for aluminum bronzes and their limited ability to embed dirt. That class-level guidance is a reason to qualify lubrication and cleanliness; it is not evidence that every C95400 bearing works dry or shares another bronze's operating limits. [CDA sleeve-bearing guide, aluminum-bronze discussion](https://www.copper.org/publications/pub_list/pdf/sleevebearing_a1063_06.pdf)

For replacement parts, compare the entire bearing system before substituting C95400 for a tin or leaded bronze. A stronger alloy can still be unsuitable for the shaft, debris level, lubrication regime or required conformability. Establish wear and functional acceptance in representative service or an appropriate qualification test.

## Machining, joining and environment

Concast gives a **machinability rating of 60**. Treat it as a comparative rating, not a spindle-speed multiplier, cycle-time promise or guaranteed surface finish. [Concast machining reference](https://www.concast.com/files/C95400.pdf)

Qualify tooling, workholding, chip control and finishing on the actual delivered condition. Define burr limits, edge treatment and surface acceptance at contacts, seals and highly loaded features. Preserve machining allowance and inspection access where casting variation or internal condition matters.

For joining, use a procedure appropriate to the actual casting and condition, with defined preparation, filler where applicable, thermal cycle and inspection. Determine how local heating changes the material state. Parent-stock tensile strength cannot establish weld or braze strength, leak tightness or fatigue performance.

Specify chemical exposure by medium, concentration, temperature, flow and duration. “Aluminum bronze” and a marine application listing do not establish immunity to all corrosion mechanisms or compatibility with arbitrary seawater service. Evaluate the actual alloy, condition and assembly, including contact with dissimilar materials and cleaning chemicals.

## Release record and source dates

Retain supplier, heat/lot, alloy, casting standard, delivered condition, drawing revision and required inspection/test results. Review substitutions against mechanical, tribological, environmental and process requirements together.

Sources reviewed November 1, 2026. The cited Concast PDFs contain no explicit printed revision date; both identify **ASTM B505/B505M-23** as their table basis, which is not a publication date for the PDFs. Aviva's cited page likewise provides no technical revision date. The CDA guide's filename is not treated as a verified revision date.

## Related reference

[Grades, conditions and material selection](../grades-tempers-and-conditions.md)