Copper Alloy C66900-H06
Supply condition
UNS C66900
H06 = extra hard
Use for flat springs, wear washers and shims where high yield strength matters more than bend ductility.
Values for the H06 condition
Other C66900 tempers and conditions
C66900 is listed in 8 conditions; see the grade overview at C66900.
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 | — |
H06This page 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-H06?
C66900-H06 is C66900 supplied in the H06 condition — use for flat springs, wear washers and shims where high yield strength matters more than bend ductility. C66900-H06 has a yield strength of 640 MPa (92.8 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 95% of copper alloy grades. Elongation at break is 5% and the elastic modulus is 105 GPa (15.2 Msi). C66900-H06 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). H04 is the default condition FabDigit quotes; H06 is available on request or by drawing note.
Advantages
- High strength — 640 MPa (92.8 ksi), better than 95% of copper alloy grades
Limitations
- Limited service temperature — 145°C (293 °F), worse than 100% of copper alloy grades
- 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 ductility — 5%, worse than 93% of copper alloy grades
- Limited formability — 18/100, worse than 75% of copper alloy grades
C66900-H06 properties
Typical room-temperature values for C66900-H06; 10 are specific to this condition. Other listed values are C66900 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C66900-H06 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-H06 has a yield strength of 640 MPa (92.8 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 95% of copper alloy grades. Elongation at break is 5% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
C66900-H06 is rated for continuous service to 145°C (293 °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-H06 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-H06 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-H06's machinability is poor (30/100, worse than 67% of copper alloy grades); weldability fair (40/100); formability poor (18/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C66900-H06
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.
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.
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 | — |
C66900-H06 — frequently asked
What is C66900-H06 used for?
C66900-H06 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-H06?
C66900-H06 has a typical yield strength of 640 MPa (92.8 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 95% of copper alloy grades. Strength varies by condition: see the 8 listed tempers.
Is C66900-H06 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-H06 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-H06?
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-H06 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-H06?
C66900-H06 is rated for continuous use to about 145°C (293 °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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.