Copper Alloy C48500
UNS C48500 · ASTM B21 · JIS C4860
C48500 is a free-cutting naval brass, a Cu-40Zn-1Sn tin brass with about 1.3–2.2% Pb added, covered by ASTM B21 and close to C48200 and C4860.
Values for the H02 condition
C48500 tempers and conditions
C48500 is supplied in 10 conditions, soft to hard. H02 is the default FabDigit quotes; the values on this page are for it.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Pick when maximum ductility for bending/upsetting or minimum residual stress is required. | 160 | 385 | 40 | 85 HB | 26 % IACS |
Soft annealed | Fully soft-annealed condition with maximum ductility and lowest strength, used where heavy cold forming or upsetting follows. | 165 | 380 | 42 | 80 HB | 26 % IACS |
As forged and quenched | Pick for hot-forged marine fittings and valve bodies machined after forging. | 170 | 400 | 33 | 95 HB | 26 % IACS |
As hot extruded | Pick for large-diameter rod, shapes and free-machining stock where softness and full ductility are acceptable. | 175 | 400 | 35 | 95 HB | 26 % IACS |
As hot forged and air cooled | Hot-forged leaded naval brass cooled in air, giving a soft, low-residual-stress alpha+beta structure with good machinability and moderate strength. | 175 | 400 | 33 | 95 HB | 26 % IACS |
Light annealed | Lightly annealed to a fine partially recrystallised grain size, balancing moderate strength with useful cold formability. | 200 | 400 | 35 | 92 HB | 26 % IACS |
Quarter hard | Pick for rod/bar needing better straightness and finish than M30 but still some bending ductility. | 230 | 430 | 30 | 110 HB | 26 % IACS |
H02Default Half hard | Standard stocked condition for free-machining marine rod, valve stems and screw-machine parts. | 280 | 470 | 25 | 125 HB | 26 % IACS |
Drawn and stress relieved | Cold-drawn rod/bar given a low-temperature stress relief, retaining most drawn strength while cutting residual stress and season-cracking risk. | 310 | 450 | 20 | 125 HB | 26 % IACS |
Full hard | Pick for small-diameter rod and wire needing maximum strength and stiffness; very limited bending. | 390 | 540 | 13 | 150 HB | 25 % IACS |
What is C48500?
C48500 is a free-cutting naval brass, a Cu-40Zn-1Sn tin brass with about 1.3–2.2% Pb added, covered by ASTM B21 and close to C48200 and C4860. The tin gives seawater corrosion and dezincification resistance while the lead breaks chips for high-speed turning at roughly 80% of C36000, with 280 MPa yield, 470 MPa tensile, 25% elongation and 125 HB. Limits are the lack of arc weldability due to lead, only fair cold formability (rating 35), continued dezincification and SCC risk in ammonia or hot high-velocity seawater, and lead-free potable-water regulations. Choose unleaded C46400 where welding or forming is required. C48500 has a density of 8.41 g/cm³ (0.304 lb/in³), lighter than 72% of copper alloy grades. It melts at 875°C (1,607 °F). C48500 has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 470 MPa (68.2 ksi) — stronger than 59% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 100 GPa (14.5 Msi).
What is C48500 used for?
- Naval brass fasteners
- Valve stems and seats
- Bushings and bearings
- Marine shafting
- Pump components
- Turned marine hardware
- Hose and pipe fittings
Advantages
- Easy to machine — 80/100, better than 86% of copper alloy grades
Limitations
- Difficult to weld — 20/100, worse than 88% of copper alloy grades
- Low stiffness — 100 GPa (14.5 Msi), worse than 82% of copper alloy grades
C48500 properties
Typical room-temperature values for C48500-H02; bars are the position among copper alloy grades.
Physical3
C48500 has a density of 8.41 g/cm³ (0.304 lb/in³), lighter than 72% of copper alloy grades. It melts at 875°C (1,607 °F).
Mechanical11
C48500 has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 470 MPa (68.2 ksi) — stronger than 59% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 100 GPa (14.5 Msi).
Thermal6
C48500 is rated for continuous service to 200°C (392 °F). It conducts heat at 116 W/m·K (67 BTU/hr·ft·°F), better than 64% of copper alloy grades. Thermal expansion is 21.2 µm/m·K (11.8 µin/in·°F).
Electrical3
C48500 conducts electricity at 26 % IACS, better than 63% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 86% of copper alloy grades.
Sustainability4
Producing a kilogram of C48500 takes about 55 MJ of energy and emits 3.6 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 65%.
Manufacturability7
C48500's machinability is very good (80/100, better than 86% of copper alloy grades); weldability poor (20/100); formability fair (35/100).
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. C48500 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C48500
Is C48500 easy to machine?
Excellent free-cutting behaviour (~80 % of C36000); use high speeds, positive-rake carbide or HSS, light lubrication, expect short chips.
Can C48500 be welded?
Not suited to fusion welding because of lead and zinc fuming; solder or braze instead, or mechanically fasten.
Can C48500 be formed, bent or molded?
Hot working/forging above ~650 °C is excellent; cold bending and heading are only fair — anneal or specify O61 for severe forming.
Manufacturability
The process limits FabDigit applies to C48500. Every C48500 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better80 / 100 |
|---|---|
| ISO material group | N.5 |
| Cutting speed (rough / finish) | 180 / 220 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 6× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Fair35 / 100 |
|---|---|
| Weldability | Poor20 / 100 |
| Bendable | Yes |
C48500 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 |
|---|---|---|
| Cu | 59 – 62 | 60.5 |
| Sn | 0.5 – 1 | 0.75 |
| Pbfree-cutting addition | 1.3 – 2.2 | 1.8 |
| Fe | ≤ 0.1 | |
| Znremainder, nominally ~37 % | balance |
What surface finishes work on C48500?
Takes bright polishing, tin, nickel or chrome plating well; use BTA/chromate or clear lacquer to prevent tarnish; avoid ammonia-based cleaners (SCC risk).
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).
Passivation
Plating
Organic Coating
Equivalent designations
Standards and trade names that resolve to Copper Alloy C48500 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B21
- JIS
- C4860
- Also called
- Leaded Naval Brass
- Similar grades
- C48200
How much does C48500 cost?
C48500 is a specialty-cost copper alloy ($$$$$), pricier than about 57% 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.
C48500 — frequently asked
What is C48500 used for?
C48500 is typically used for naval brass fasteners, valve stems and seats, bushings and bearings, marine shafting, pump components and turned marine hardware. In short: high-strength marine brass.
What is the yield strength of C48500?
C48500 has a typical yield strength of 280 MPa (40.6 ksi) and a tensile strength of 470 MPa (68.2 ksi) — stronger than 59% of copper alloy grades. Strength varies by condition: see the 10 listed tempers.
Is C48500 easy to machine?
Yes — machinability is rated very good (80/100, better than 86% of copper alloy grades). Excellent free-cutting behaviour (~80 % of C36000); use high speeds, positive-rake carbide or HSS, light lubrication, expect short chips.
Can C48500 be welded?
Not readily — weldability is rated poor (20/100). Not suited to fusion welding because of lead and zinc fuming; solder or braze instead, or mechanically fasten.
What surface finishes work on C48500?
Takes bright polishing, tin, nickel or chrome plating well; use BTA/chromate or clear lacquer to prevent tarnish; avoid ammonia-based cleaners (SCC risk).
Can C48500 be formed, bent or molded?
Hot working/forging above ~650 °C is excellent; cold bending and heading are only fair — anneal or specify O61 for severe forming.
What is the maximum service temperature of C48500?
C48500 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C48500-H02 and C48500-O61?
H02 is the default condition — standard stocked condition for free-machining marine rod, valve stems and screw-machine parts. O61: pick when maximum ductility for bending/upsetting or minimum residual stress is required. Yield strength is 280 MPa in H02 versus 160 MPa in O61.
How much does C48500 cost?
C48500 is a specialty-cost copper alloy ($$$$$), pricier than about 57% 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.
Can FabDigit make parts in C48500?
Yes — C48500 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B21/B21M — Naval Brass Rod, Bar, and Shapes — ASTM (2021)
- ASTM B124/B124M — Copper and Copper-Alloy Forging Rod, Bar, and Shapes — ASTM (2020)
- CDA Alloy Datasheet C48500 (copper.org) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties of Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — 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.