Copper Alloy C99700
UNS C99700 · ASTM B584, B763
C99700 is a cast copper-manganese-nickel-zinc "white brass" covered by ASTM B584 and B763, in which manganese and nickel give a silver-white colour in the as-cast condition without plating.
Reference datasheet — C99700 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the M01 condition
C99700 tempers and conditions
C99700 is supplied in 7 conditions, soft to hard. M01 is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Stress-relief annealed casting | Low-temperature (about 300–350 °C) stress relief for parts that will be heavily machined or exposed to ammonia-bearing atmospheres. | 210 | 435 | 28 | 115 HB | 3 % IACS |
M01Default As sand cast | Standard ASTM B584 sand-cast condition for architectural and marine hardware of medium size. | 230 | 450 | 25 | 125 HB | 3 % IACS |
As chill cast | Pick for thin, intricate decorative parts to ASTM B763 where as-cast surface must be near-final before polishing. | 235 | 450 | 22 | 130 HB | 3 % IACS |
As pressure die cast | For rings, sleeves and bushings needing dense, porosity-free sections. | 250 | 470 | 22 | 135 HB | 3 % IACS |
As plaster cast | Continuous-cast bar/tube stock for machined decorative components; most uniform structure of the cast forms. | 260 | 480 | 20 | 140 HB | 3 % IACS |
As centrifugally cast | Chill-cast condition giving finer grain, higher strength and hardness for repeat-production hardware. | 275 | 485 | 20 | 145 HB | 3 % IACS |
As continuous cast | High-volume small decorative hardware; highest as-cast strength but limited section size and die life. | 290 | 500 | 15 | 150 HB | 3 % IACS |
What is C99700?
C99700 is a cast copper-manganese-nickel-zinc "white brass" covered by ASTM B584 and B763, in which manganese and nickel give a silver-white colour in the as-cast condition without plating. Typical default values are 450 MPa tensile strength, 230 MPa yield, 25% elongation and 125 HB, so it carries moderate structural load as well as serving decorative roles, and it is produced as sand, permanent-mould and continuous castings. Electrical conductivity is only 3% IACS and machinability runs about 30% of free-cutting brass, so cycle times and tooling costs are high. Where chip control matters more than a fully unleaded chemistry, the leaded variant C99750 is the nearest alternative. C99700 has a density of 8.03 g/cm³ (0.29 lb/in³), lighter than 87% of copper alloy grades. It melts at 880°C (1,616 °F). C99700 has a yield strength of 230 MPa (33.4 ksi) and a tensile strength of 450 MPa (65.3 ksi) — stronger than 51% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 105 GPa (15.2 Msi).
What is C99700 used for?
- decorative hardware
- architectural fittings
- marine hardware
- art castings
Advantages
- Polishes to a fine finish — 88/100, better than 97% of copper alloy grades
Limitations
- Low electrical conductivity — 3 % IACS, worse than 100% of copper alloy grades
- Poor heat conductor — 27 W/m·K (15.6 BTU/hr·ft·°F), worse than 97% of copper alloy grades
- Limited formability — 18/100, worse than 75% of copper alloy grades
C99700 properties
Typical room-temperature values for C99700-M01; bars are the position among copper alloy grades.
Physical3
C99700 has a density of 8.03 g/cm³ (0.29 lb/in³), lighter than 87% of copper alloy grades. It melts at 880°C (1,616 °F).
Mechanical14
C99700 has a yield strength of 230 MPa (33.4 ksi) and a tensile strength of 450 MPa (65.3 ksi) — stronger than 51% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
C99700 is rated for continuous service to 230°C (446 °F). It conducts heat at 27 W/m·K (15.6 BTU/hr·ft·°F), worse than 97% of copper alloy grades. Thermal expansion is 20 µm/m·K (11.1 µin/in·°F).
Electrical3
C99700 conducts electricity at 3 % IACS, worse than 100% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (65/100), better than 58% of copper alloy grades.
Sustainability4
Producing a kilogram of C99700 takes about 55 MJ of energy and emits 3.8 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 75%.
Manufacturability8
C99700's machinability is poor (32/100, worse than 57% of copper alloy grades); weldability fair (35/100); formability poor (18/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the copper alloy family
Yield strength against density for every copper alloy grade FabDigit runs. C99700 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C99700
Is C99700 easy to machine?
Tough, gummy chips — use sharp positive-rake carbide, moderate speed with generous coolant; rating ≈30 % of free-cutting brass.
Can C99700 be welded?
Best joined by brazing or silver soldering; GTAW possible with matching Cu-Mn filler but zinc fume, porosity and hot cracking must be controlled.
Can C99700 be formed, bent or molded?
Foundry alloy only — good fluidity, use chills and ample risering to avoid centreline shrinkage; degas and keep pouring temperature ~1050–1100 °C to limit Mn/Zn loss.
C99700 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Mn | 11 – 15 | 13 |
| Zn | 19 – 25 | 22 |
| NiNi + Co | 4 – 6 | 5 |
| Al | 0.5 – 3 | 1.5 |
| Fe | ≤ 1 | 0.4 |
| Pb | ≤ 2 | 0.5 |
| Cu54.0 % min per ASTM B584 | ≥ 54 (balance) |
What surface finishes work on C99700?
Takes a bright silver-like mirror polish directly; can be brushed, satin-finished, PVD-coated or clear-lacquered — plating is usually unnecessary.
Surface treatments FabDigit runs on copper alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Equivalent designations
Standards and trade names that resolve to Copper Alloy C99700 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B584B763
How much does C99700 cost?
C99700 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
C99700 — frequently asked
What is C99700 used for?
C99700 is typically used for decorative hardware, architectural fittings, marine hardware and art castings. In short: silver-white without plating; strongest decorative cast brass; slow-machining copper alloy.
What is the yield strength of C99700?
C99700 has a typical yield strength of 230 MPa (33.4 ksi) and a tensile strength of 450 MPa (65.3 ksi) — stronger than 51% of copper alloy grades. Strength varies by condition: see the 7 listed tempers.
Is C99700 easy to machine?
Not especially — machinability is rated poor (32/100, worse than 57% of copper alloy grades). Tough, gummy chips — use sharp positive-rake carbide, moderate speed with generous coolant; rating ≈30 % of free-cutting brass.
Can C99700 be welded?
With care — weldability is rated fair (35/100). Best joined by brazing or silver soldering; GTAW possible with matching Cu-Mn filler but zinc fume, porosity and hot cracking must be controlled.
What surface finishes work on C99700?
Takes a bright silver-like mirror polish directly; can be brushed, satin-finished, PVD-coated or clear-lacquered — plating is usually unnecessary.
Can C99700 be formed, bent or molded?
Foundry alloy only — good fluidity, use chills and ample risering to avoid centreline shrinkage; degas and keep pouring temperature ~1050–1100 °C to limit Mn/Zn loss.
What is the maximum service temperature of C99700?
C99700 is rated for continuous use to about 230°C (446 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C99700-M01 and C99700-M07?
M01 is the default condition — standard ASTM B584 sand-cast condition for architectural and marine hardware of medium size. M07: high-volume small decorative hardware; highest as-cast strength but limited section size and die life. Yield strength is 230 MPa in M01 versus 290 MPa in M07.
How much does C99700 cost?
C99700 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM B584 — Standard Specification for Copper Alloy Sand Castings for General Applications — ASTM International (2022)
- ASTM B763 — Copper Alloy Sand Castings for Valve Applications / investment cast product data — ASTM International (2021)
- CDA Alloy Database — C99700 white manganese bronze — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials (copper alloys) — ASM International (2005)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.