Copper Alloy C66900
UNS C66900
C66900 is a higher-manganese variant of manganese brass supplied as strip in O60 and H01 through H10 tempers, giving more strength and wear resistance than C66700.
Reference datasheet — C66900 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 H04 condition
C66900 tempers and conditions
C66900 is supplied in 8 conditions, soft to hard. H04 is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Pick when maximum drawability/bendability is needed before subsequent forming or in-service work hardening. | 205 | 480 | 45 | 55 HRB | — |
Quarter hard | Lightest rolled temper — use when moderate strength must be combined with substantial bending and forming. | 380 | 585 | 22 | 75 HRB | — |
Half hard | General-purpose stamping temper balancing strength with 90° bend capability across the grain. | 450 | 625 | 15 | 82 HRB | — |
Three-quarter hard | Intermediate step when H02 lacks yield strength but H04 is too stiff to form. | 510 | 660 | 11 | 85 HRB | — |
H04Default Full hard | Most commonly stocked condition — high strength and wear resistance for flat structural parts and gentle bends. | 565 | 700 | 7 | 88 HRB | — |
Extra hard | Use for flat springs, wear washers and shims where high yield strength matters more than bend ductility. | 640 | 760 | 5 | 92 HRB | — |
Spring hard | Spring-quality strip for contacts, clips and retaining elements requiring high elastic limit. | 690 | 800 | 4 | 95 HRB | — |
Extra spring hard | Highest-strength rolled condition; specify only for flat or large-radius parts with minimal forming. | 725 | 830 | 3 | 97 HRB | — |
What is C66900?
C66900 is a higher-manganese variant of manganese brass supplied as strip in O60 and H01 through H10 tempers, giving more strength and wear resistance than C66700. Default properties are 565 MPa yield, 700 MPa tensile, 7 % elongation and 88 HRB, with service to 150 °C, so it suits loaded structural and wear components. Formability is low (score 25) in the harder tempers, it is unleaded and machines at about 30 % of free-cutting brass, and it is not anodizable. Use C66700 where deep drawing or 25 % elongation is required. C66900 has a density of 8.1 g/cm³ (0.293 lb/in³), lighter than 86% of copper alloy grades. It melts at 880°C (1,616 °F). C66900 has a yield strength of 565 MPa (81.9 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 93% of copper alloy grades. Elongation at break is 7% and the elastic modulus is 105 GPa (15.2 Msi).
What is C66900 used for?
- gears and wear parts
- structural fasteners
- marine hardware
Advantages
- High strength — 565 MPa (81.9 ksi), better than 93% of copper alloy grades
Limitations
- Low electrical conductivity — 4.5 % IACS, worse than 98% 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 service temperature — 150°C (302 °F), worse than 96% of copper alloy grades
- Limited ductility — 7%, worse than 86% of copper alloy grades
C66900 properties
Typical room-temperature values for C66900-H04; bars are the position among copper alloy grades.
Physical3
C66900 has a density of 8.1 g/cm³ (0.293 lb/in³), lighter than 86% of copper alloy grades. It melts at 880°C (1,616 °F).
Mechanical12
C66900 has a yield strength of 565 MPa (81.9 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 93% of copper alloy grades. Elongation at break is 7% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
C66900 is rated for continuous service to 150°C (302 °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
C66900 conducts electricity at 4.5 % IACS, worse than 98% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 57% of copper alloy grades.
Sustainability4
Producing a kilogram of C66900 takes about 55 MJ of energy and emits 3.5 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 40%.
Manufacturability8
C66900's machinability is poor (30/100, worse than 67% of copper alloy grades); weldability fair (40/100); formability poor (25/100).
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. C66900 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C66900
Is C66900 easy to machine?
Unleaded and work-hardened: use sharp carbide, positive rake, 0.05–0.15 mm/rev feeds and flood coolant; expect gummy chips and ~30 % of free-cutting brass throughput.
Can C66900 be welded?
Best joined by resistance spot/seam welding or silver brazing; fusion welding causes zinc fuming, porosity and loss of temper — use local extraction and avoid heating cold-worked strip above ~250 °C.
Can C66900 be formed, bent or molded?
Form in O60/H01–H02; in H04 and harder restrict to gentle bends with generous radii and bend across the rolling direction, and stress-relieve 200–260 °C to prevent season cracking.
C66900 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 |
|---|---|---|
| Cuper CDA/UNS registration for C66900; confirm against mill certificate | 63 – 68 | 65.5 |
| Mnprincipal strengthening addition — distinguishes C66900 from C66700/C66800 | 11 – 13 | 12 |
| Fe | ≤ 0.5 | |
| Al | ≤ 0.5 | |
| Pb | ≤ 0.05 | |
| Znremainder, nominally ~22–24 % | balance |
What surface finishes work on C66900?
Not anodizable — bright dip and clear lacquer, or nickel/chrome/tin plating after thorough oxide removal (Mn-rich film needs activated cleaning); polishes to a bright warm finish.
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).
How much does C66900 cost?
C66900 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.
C66900 — frequently asked
What is C66900 used for?
C66900 is typically used for gears and wear parts, structural fasteners and marine hardware. In short: highest-strength manganese brass; 700 MPa tensile strip; wear-resistant structural grade.
What is the yield strength of C66900?
C66900 has a typical yield strength of 565 MPa (81.9 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 93% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C66900 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 67% of copper alloy grades). Unleaded and work-hardened: use sharp carbide, positive rake, 0.05–0.15 mm/rev feeds and flood coolant; expect gummy chips and ~30 % of free-cutting brass throughput.
Can C66900 be welded?
With care — weldability is rated fair (40/100). Best joined by resistance spot/seam welding or silver brazing; fusion welding causes zinc fuming, porosity and loss of temper — use local extraction and avoid heating cold-worked strip above ~250 °C.
What surface finishes work on C66900?
Not anodizable — bright dip and clear lacquer, or nickel/chrome/tin plating after thorough oxide removal (Mn-rich film needs activated cleaning); polishes to a bright warm finish.
Can C66900 be formed, bent or molded?
Form in O60/H01–H02; in H04 and harder restrict to gentle bends with generous radii and bend across the rolling direction, and stress-relieve 200–260 °C to prevent season cracking.
What is the maximum service temperature of C66900?
C66900 is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C66900-H04 and C66900-O60?
H04 is the default condition — most commonly stocked condition — high strength and wear resistance for flat structural parts and gentle bends. O60: pick when maximum drawability/bendability is needed before subsequent forming or in-service work hardening. Yield strength is 565 MPa in H04 versus 205 MPa in O60.
How much does C66900 cost?
C66900 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
- CDA/UNS Copper Alloy Registration & Alloy Data — C669xx manganese brasses — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials (brasses, dezincification, SCC) — ASM International (2005)
- ASTM B36/B36M — Brass Plate, Sheet, Strip and Rolled Bar (temper designations per ASTM B601) — ASTM International (2018)
- ASTM B601 — Temper Designations for Copper and Copper Alloys — ASTM International (2019)
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.