# UNS C46400 Naval Brass

**UNS C46400 is the standard uninhibited naval brass: a 60/40 copper-zinc alloy with a 0.5-1.0 % tin addition that raises its resistance to corrosion and erosion in seawater.** It is covered by ASTM B21 for rod, bar and shapes, by ASTM B124 and B283 for forgings, and by ASTM B171 / ASME SB-171 for condenser tube plates. Jiangyin Jiangnan Metal forges, machines, drills and certifies C46400 tube sheets, discs, rings, flanges and bars to customer drawing.

Also known as: C46400, Alloy 464, C464, naval brass (uninhibited), CuZn39Sn1, CW719R, CZ112, ASTM B21 C46400, ASME SB-171 C46400, AMS 4611, AMS 4612, QQ-B-639, HSn62-1.

- Canonical page: https://www.steelforgepieces.com/Alloy-Steel/UNS-C46400.html
- Publisher: Jiangyin Jiangnan Metal Co., Ltd., No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Contact: +86 189 2135 9659 | sales@steelforgepieces.com
- Published 2026-09-18, last technically reviewed 2026-09-18

## C46400 at a glance

| Item | Value |
| --- | --- |
| UNS number | C46400 (wrought copper-zinc-tin alloy, tin brass) |
| Nominal composition | Cu 60 %, Zn 39.25 %, Sn 0.75 % |
| Composition limits | Cu 59.0-62.0, Sn 0.50-1.0, Pb 0.20 max, Fe 0.10 max, Zn remainder |
| Density | 8.41 g/cm3 (0.304 lb/in3) |
| Melting range | 888-899 °C (1630-1650 °F), solidus to liquidus |
| Tensile strength | 386-607 MPa (56-88 ksi), temper dependent |
| Forgeability rating | 90 of 100 |
| Machinability rating | 30 (free-cutting brass C36000 = 100) |
| Hot working range | 649-816 °C (1200-1500 °F) |
| Governing specifications | ASTM B21, B124, B171, B283; ASME SB-171, SB-283; AMS 4611, AMS 4612 |

## 1. What C46400 is, and why tin is in it

C46400 is a duplex alpha-plus-beta brass. A plain 60/40 brass has the strength and hot workability that the beta phase gives, but it corrodes in seawater. Substituting roughly three-quarters of a percent of tin for an equal quantity of zinc keeps the strength and adds resistance to corrosion and erosion in saline and brackish water. That substitution is what turned 60/40 brass into naval brass, and the alloy has been specified for marine and condenser service ever since.

The alloy is strong for a brass, reaching about 607 MPa in hard tempers, with good resistance to wear, galling and fatigue. It is also exceptionally hot workable, carrying a forgeability rating of 90 against 100 for the best-forging brass, so complex sections can be close-die forged instead of machined from solid. There is no deliberate lead addition, which matters for potable-water hardware now that leaded free-cutting brasses are restricted in that service.

Against that, machinability is rated 30 against the free-cutting benchmark, so C46400 cuts slowly and produces stringy chips; heavy sections are usually cheaper forged close to shape and then finish-machined. C46400 is also the uninhibited grade, carrying no arsenic, antimony or phosphorus addition, so its dezincification resistance is good rather than excellent. Section 06 covers where that matters and what to specify instead.

## 2. Chemical composition of UNS C46400

Composition limits are identical across ASTM B21 (rod, bar and shapes), ASTM B124 (forging rod, bar and shapes), ASTM B283 (die forgings) and ASTM B171 (condenser tube plates). Copper plus the sum of named elements must be at least 99.6 %.

| Element | Minimum % | Maximum % | Nominal % | Role in the alloy |
| --- | --- | --- | --- | --- |
| Copper (Cu) | 59.0 | 62.0 | 60 | Base. Sets the alpha/beta phase balance |
| Zinc (Zn) | - | Remainder | 39.25 | Strength and hot workability via the beta phase |
| Tin (Sn) | 0.50 | 1.0 | 0.75 | Corrosion and erosion resistance in seawater |
| Lead (Pb) | - | 0.20 | residual | Not added. Residual only |
| Iron (Fe) | - | 0.10 | residual | Not added. Residual only |

Single values are maximums. Limits per ASTM B21/B21M and the Copper Development Association alloy record for C46400.

**On lead and RoHS.** No lead is added to C46400 and production heats normally run well below 0.10 % Pb, but the specification permits up to 0.20 % max, which is above the 0.1 % RoHS substance threshold on paper. RoHS Annex III exemption 6(c) covers copper alloy containing up to 4 % lead by weight, so the alloy is normally compliant by exemption. Where the actual figure matters, the measured lead content is stated on the EN 10204 3.1 certificate. Ask for it at enquiry stage.

## 3. Physical, thermal and electrical properties

All values are at room temperature, 20 °C (68 °F), unless a range is stated.

| Property | Metric | Imperial |
| --- | --- | --- |
| Density | 8.41 g/cm3 | 0.304 lb/in3 |
| Melting point, solidus | 888 °C | 1630 °F |
| Melting point, liquidus | 899 °C | 1650 °F |
| Thermal conductivity | 116 W/m·K | 67 Btu/ft·h·°F |
| Coefficient of thermal expansion, 20-300 °C | 21.2 µm/m·°C | 11.8 µin/in·°F |
| Specific heat capacity | 377 J/kg·K | 0.09 Btu/lb·°F |
| Electrical conductivity | 26 % IACS | 26 % IACS |
| Electrical resistivity | approx. 6.6 µΩ·cm | approx. 39.9 Ω·cmil/ft |
| Modulus of elasticity, tension | 103 GPa | 15 000 ksi |
| Modulus of rigidity (shear) | 38.6 GPa | 5 600 ksi |
| Poisson's ratio | approx. 0.34 | approx. 0.34 |
| Magnetic response | Non-magnetic | Non-magnetic |

Values from the Copper Development Association record for C46400. Thermal conductivity of 116 W/m·K is roughly 30 % that of pure copper and about seven times that of austenitic stainless steel, which is why brass remains in use for condenser tube plate.

**Two figures that are often quoted wrongly.** Several supplier data sheets list the elastic modulus of C46400 as 117 GPa (17 000 ksi) and give a single melting point of 888 °C. The CDA value is 103 GPa (15 000 ksi). And 888 °C is the solidus, not the melting point; the liquidus is 899 °C. Use the CDA figures for design calculations.

## 4. Mechanical properties by temper

There is no single tensile figure for C46400, because the temper decides it. Soft annealed rod runs about 386 MPa with 47 % elongation; hard-drawn tube reaches roughly 607 MPa with 18 %. Always state the temper on the enquiry, since strength and ductility move in opposite directions across the range below.

| Form | Temper | Code | Tensile MPa | Tensile ksi | Yield MPa | Elong. % | Hardness HRB |
| --- | --- | --- | --- | --- | --- | --- | --- |
| Rod | Soft annealed | O60 | 386-400 | 56-58 | 172-186 | 45-47 | 55-56 |
| Rod | Light annealed | O50 | 427-434 | 62-63 | 193-207 | 40-43 | 60 |
| Rod | Quarter hard | H01 | 462-483 | 67-70 | 276-331 | 25-35 | 75-80 |
| Rod | Half hard | H02 | 517-552 | 75-80 | approx. 393 | 20 | 82-85 |
| Flat products | As hot rolled | M20 | 379 | 55 | 172 | 50 | 55 |
| Flat products | Soft annealed | O60 | 400 | 58 | 172 | 49 | 56 |
| Flat products | Quarter hard | H01 | 483 | 70 | approx. 400 | 17 | 68 |
| Tube | Hard drawn | H80 | 607 | 88 | - | 18 | 95 |

Typical values, not guaranteed minima; actual figures vary with section size and the amount of cold work. Yield is measured at 0.5 % extension under load. Purchase minima are set by the governing specification: ASTM B21 for rod, bar and shapes, ASTM B171 for tube plate. Source: Copper Development Association property tables for C46400.

**For tube sheets, specify the temper as well as the standard.** Condenser tube plate is normally ordered in the as-rolled or annealed condition so that tube holes can be drilled and the tubes expanded without cracking. A half-hard plate will fight you at the tube-rolling stage. State the tube expansion method on the enquiry and the temper is chosen to suit it.

## 5. Forging, heat treatment, machining and joining

### Hot working and forging

C46400 is one of the better-forging copper alloys, rated 90 out of 100 on the CDA forgeability scale, and its capacity for hot forming is rated excellent. The hot working range is 649-816 °C (1200-1500 °F). Above that the beta phase coarsens and the alloy becomes hot short; below it the press loads rise sharply. In practice, complex valve bodies, hub cones and heavy sections are forged close to final shape rather than hogged out of plate, which saves both material and machining hours on an alloy whose machinability rating is only 30.

### Annealing and stress relief

Annealing is carried out at 427-593 °C (800-1100 °F). Cold-worked parts destined for marine or ammonia-bearing service should be stress relieved at the low end of that range, since residual tensile stress from cold forming is the largest contributor to stress corrosion cracking in brasses. C46400 is not heat treatable in the precipitation-hardening sense. Strength comes from cold work, not from ageing.

### Machining

Rate the alloy at about 30 % of free-cutting brass C36000. Plan for lower surface speeds, sharp positive-rake tooling and good chip evacuation; the chips are stringier than leaded brass and will wrap if feeds are too light. Cold working capacity is rated fair, so heavy cold forming needs intermediate anneals.

### Joining

| Process | Rating | Practical note |
| --- | --- | --- |
| Soldering | Excellent | Preferred route for light assemblies |
| Brazing | Excellent | Preferred route for structural joints |
| Oxyacetylene welding | Good | Zinc fume control required |
| Gas shielded arc welding | Fair | Zinc volatilisation causes porosity |
| Coated metal arc welding | Not recommended | Use brazing instead |
| Spot welding | Good | - |
| Butt welding | Good | - |
| Seam welding | Fair | - |

Common fabrication processes: blanking, drawing, forming and bending, heading and upsetting, hot forging and pressing, hot heading and upsetting, shearing. Ratings per the Copper Development Association.

**Why brasses are brazed rather than arc welded.** Zinc boils at 907 °C, barely above the alloy's own liquidus. Arc processes drive zinc out of the weld pool as fume. That leaves porosity, shifts the composition of the joint away from specification, and produces a metal-fume-fever hazard. Where a joint in C46400 must be welded rather than brazed, agree the procedure and the filler before the order is placed.

## 6. Corrosion behaviour and service limits

C46400 performs well in clean seawater, brackish water and moderately polluted river water. It is not a universal corrosion alloy, and four limits decide most applications.

### 6.1 Dezincification, and why the inhibited grades exist

Dezincification is selective leaching of zinc out of the brass, leaving a porous copper residue with almost no strength. The tin in C46400 slows it, which is why naval brass outperforms plain 60/40 brass, but C46400 is the uninhibited grade. Where the water is stagnant, warm, polluted or high in chloride, specify one of the inhibited naval brasses instead:

| UNS | Name | Inhibitor | Use when |
| --- | --- | --- | --- |
| C46400 | Naval brass, uninhibited | None | General marine, structural, forged and machined parts |
| C46500 | Naval brass, arsenical | Arsenic | Condenser and heat-exchanger service where dezincification is the controlling risk |
| C46600 | Naval brass, antimonial | Antimony | As C46500, where arsenic is restricted by the end user |
| C46700 | Naval brass, phosphorized | Phosphorus | As C46500, alternative inhibitor |

All four share the same mechanical and physical properties in practice. The inhibitor is a trace addition; it changes corrosion behaviour, not strength. If a drawing calls simply for "naval brass" and the duty is condenser water, ask whether C46500 was intended.

### 6.2 Ammonia and amine stress corrosion cracking

Every brass is susceptible to stress corrosion cracking in ammonia, ammonium compounds and amines, and C46400 is no exception. Two conditions have to coincide, a tensile stress and the environment, so the mitigation is to remove one of them. Stress relieve after cold work, avoid over-expanding tubes into tube sheets, and keep the alloy out of ammonia-dosed circuits. In power-plant condensers this matters at the air removal section, where ammonia concentrates.

### 6.3 Flow velocity and impingement

Brasses are velocity-limited in seawater. Above the design velocity the protective film is stripped mechanically and impingement attack begins downstream of any turbulence, at tube inlets, partial obstructions and sharp entries. Copper-nickel alloys tolerate considerably higher velocities than naval brass and are the normal step up when the water box design cannot keep velocity down. Confirm the permitted velocity against the applicable design code for your duty rather than against a generic figure.

### 6.4 Galvanic pairing and temperature

C46400 sits near the noble end of the copper group but is anodic to titanium, graphite and the superaustenitic stainless steels. A naval brass tube sheet paired with titanium tubes in seawater is an active galvanic couple with a very unfavourable area ratio, and it will need cathodic protection or a different tube sheet material. Pairing with copper-nickel or with other copper alloys is benign. On temperature, copper alloys are restricted to moderate temperatures in pressure service. Check the allowable stress table in ASME BPVC Section II Part D for C46400 at your design temperature before fixing the material.

**In summary.** For clean flowing seawater, brackish water, fresh water and marine atmosphere, C46400 is a sound and economical choice. For stagnant or polluted water, ammonia-bearing circuits, high flow velocity, or a titanium-tubed exchanger, look at C46500, a copper-nickel, or a different material class instead.

## 7. Specifications and international equivalents

### Governing specifications by product form

| Product form | Standard | Title |
| --- | --- | --- |
| Rod, bar, shapes | ASTM B21 / B21M | Naval brass rod, bar and shapes |
| Forging rod, bar, shapes | ASTM B124 / B124M | Copper and copper-alloy forging rod, bar and shapes |
| Die forgings, hot pressed | ASTM B283 / B283M, ASME SB-283 | Copper and copper alloy die forgings (hot pressed) |
| Condenser tube plate | ASTM B171 / B171M, ASME SB-171 | Copper alloy plate and sheet for pressure vessels, condensers and heat exchangers |
| Clad steel plate | ASTM B432 | Copper and copper alloy clad steel plate |
| Plate, sheet, bar, strip | QQ-B-639 | Brass, naval, flat products (US federal) |
| Bar and rod, half hard | AMS 4611 | Brass bars and rods, naval, half-hard |
| Bar and rod, hard | AMS 4612 | Brass bars and rods, naval, hard temper |
| Bolts, screws, studs | ASTM F468 | Nonferrous bolts, hex cap screws and studs for general use |
| Nuts | ASTM F467 | Nonferrous nuts for general use |
| General wrought alloys | SAE J461, J463 | Wrought and cast copper alloys |

### International cross-reference

| System | Designation | Note |
| --- | --- | --- |
| USA, UNS | C46400 (Alloy 464, C464) | The reference grade on this page |
| Europe, EN | CuZn39Sn1 / CW719R | Closest chemical match. EN 12163, 12164, 12165, 12167 |
| Europe, EN (alternative) | CuZn36Sn1Pb / CW712R | Also cross-referenced commercially; higher Cu, contains lead. Confirm which is intended |
| UK, BS | CZ112 (BS 2874); CZ133 also cited | Naval brass. Trade sources differ, so check the drawing |
| Japan, JIS | C4621, C4640 (JIS H3250) | Naval brass |
| China, GB/T | HSn62-1 | Tin brass, naval brass equivalent |
| ISO | CuZn39Sn1 | Same designation as the EN chemical name |

**Equivalents are nearest matches, not interchangeable grades.** Composition windows differ between systems. CW719R and CW712R are not the same alloy, and both appear in the trade literature against C46400. A part ordered to one designation and certified to another can fail a receiving inspection even though the metal is sound. Name the governing specification and the issue on your drawing, and we will confirm in writing which grade will be supplied and how the certificate will be worded before the order is booked.

## 8. C46400 against the alternatives

| Material | Where it wins | Where it loses | Relative cost |
| --- | --- | --- | --- |
| C46400 naval brass | Clean sea and brackish water, high thermal conductivity, easy drilling and tube expansion, low cost | Uninhibited, so dezincifies in stagnant or polluted water; ammonia SCC; velocity limited | Low |
| C46500 arsenical naval brass | Same as C46400 plus real dezincification resistance | Same ammonia and velocity limits; less widely stocked | Low |
| 90/10 and 70/30 copper-nickel | Much higher permitted seawater velocity, strong biofouling resistance | Lower conductivity than brass; sensitive to sulphide-polluted water | Medium |
| 316L stainless (S31603) | Strength, general chemical service, easy sourcing and welding | Pitting and crevice corrosion in seawater and under deposits | Medium |
| Duplex 2205 (S32205) | Roughly double the strength of 316L, better chloride resistance, thinner tube sheets | Still not a seawater alloy at elevated temperature; phase-balance control needed on thick sections | Medium-high |
| 254 SMO and AL-6XN | 6 % molybdenum superaustenitics: genuine seawater capability with steel-like strength | Cost; cathodic to copper alloys, so watch mixed-material exchangers | High |
| Monel 400 | Excellent in flowing seawater, immune to chloride SCC, wide temperature range | Cost; attacked by stagnant sulphide-bearing or oxidising conditions | High |
| Alloy 825 and Alloy 20 | Sulphuric and phosphoric acid duty, mixed-acid process coolers | Overspecified and expensive for plain seawater cooling | High |
| Titanium Grade 2 | Effectively immune in seawater at any velocity | Strongly cathodic to brass and steel; galvanic design and cathodic protection required | High |

Cost bands are relative and move with the copper and nickel markets. All of the grades above are forged and machined at this works except the copper alloys and titanium, which are procured to specification. See section 9.

## 9. What Jiangyin Jiangnan Metal supplies in C46400

Jiangyin Jiangnan Metal is an integrated melting works and open-die forge in Jiangyin, Jiangsu Province, operating since 1997. The furnaces here melt steel and nickel alloys, not brass. C46400 material is procured to specification from qualified copper mills, plate to ASTM B171 / ASME SB-171 and forging stock to ASTM B21, B124 or B283. It is then formed, heat treated, machined, drilled, inspected and certified in this plant, and the copper mill's certificate is supplied alongside our own documentation. We state this plainly because a certificate that claims a melt origin it does not have is worth nothing at a receiving inspection.

### Product forms

- Tube sheets and tubesheets, drilled, grooved and finish-machined to TEMA
- Baffle plates, support plates and tube plates
- Condenser end plates and covers
- Solid discs, blanks and hubs
- Flanges: weld neck, blind, slip-on, lap joint, orifice
- Rings, retaining rings and seat rings
- Round bar, hollow bar, flat bar and blocks
- Sleeves, bushes, bushings and hollow cylinders
- Valve stems, seats and body components
- Propeller shafts, marine hardware, turnbuckle barrels

### Tube sheet configurations

Fixed and stationary tube sheets, floating tube sheets, front and rear heads. Cladded, overlaid and weld-overlay tube sheets are also produced, where a steel or low-alloy backing plate carries a C46400 face. That is the usual route when the plate is too thick or too large for solid copper alloy to be economic.

### Size envelope

| Operation | Limit | Set by |
| --- | --- | --- |
| Machined diameter | up to Ø5,000 mm | Ø5,000 mm vertical turning lathe |
| Turned length | up to 14,000 mm | C61160 horizontal lathe |
| Deep-hole boring | Ø1,600 × 10,000 mm | CNC deep-hole drilling machine |
| Heat treatment | 8,000 × 2,000 × 2,000 mm | Car-bottom furnaces, 14 on site |
| Minimum order | 10 kg | No minimum piece count |
| Lead time | 20-60 days | Depends on stock availability and machining content |

### Inspection and certification

- EN 10204 3.1 mill test certificate as standard; 3.2 witnessed by BV, DNV, LR, SGS, TÜV or your own inspector on request
- Positive material identification (PMI) by handheld alloy analyser on every heat
- Chemical analysis by optical emission spectrometry to ASTM E415
- Tensile testing on 600 kN and 300 kN machines to ASTM A370 / ISO 6892
- Dimensional and tube-hole reports; visual examination of bores by industrial endoscope
- Class approvals held by the works: CCS, BV, DNV, LR, NK

**Traceability.** Copper alloy stock arrives with the producing mill's certificate. That document, the PMI record, our own dimensional and machining records and the heat-treatment chart travel together to shipment, so a finished tube sheet traces back to the copper mill's heat number rather than stopping at "purchased plate".

## 10. Request a quotation for C46400 parts

Quotations are prepared from a drawing or a written specification. Sending the items below in the first email removes a round trip and usually gets a price back within two working days.

| # | Item | Example |
| --- | --- | --- |
| 1 | Grade and governing specification | UNS C46400 to ASTM B171 / ASME SB-171 |
| 2 | Temper, or the tube expansion method | O61 annealed, tubes roller expanded |
| 3 | Dimensions or a drawing (PDF, DWG, DXF, STEP) | Ø1,850 × 95 mm, 1,240 tube holes Ø25.4 |
| 4 | Quantity and expected repeat volume | 2 pcs, 1 spare per year |
| 5 | Delivery condition | Drilled, grooved and finish-machined |
| 6 | Certification and destination port | EN 10204 3.2 witnessed by DNV · Rotterdam |

### Sales and engineering

- **Company:** Jiangyin Jiangnan Metal Co., Ltd.
- **Plant address:** No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- **Telephone, WhatsApp, WeChat:** +86 189 2135 9659
- **Email:** sales@steelforgepieces.com
- **Business hours:** Monday to Saturday, 08:00-17:30 China Standard Time (UTC+8)
- **Minimum order:** 10 kg, no minimum piece count

Customer audits, pre-shipment inspections and third-party witness testing are welcome. Wuxi Shuofang International Airport is 30 km from the plant; Shanghai's airports are 160 km. Please arrange visits by email in advance so an English-speaking engineer is available.

## 11. Frequently asked questions about C46400

### What is UNS C46400 naval brass?

UNS C46400 is a wrought copper-zinc-tin alloy, a 60/40 brass with 0.5 to 1.0 % tin added, known commercially as naval brass, Alloy 464 or C464. The tin addition gives resistance to corrosion and erosion in seawater, which plain 60/40 brass does not have. The alloy has a duplex alpha-plus-beta structure, is strong for a brass at 386 to 607 MPa depending on temper, forges exceptionally well, and contains no deliberate lead addition.

It is specified in ASTM B21 for rod, bar and shapes, ASTM B124 and B283 for forgings, and ASTM B171 / ASME SB-171 for condenser tube plates. Typical uses are condenser tube sheets and end plates, marine hardware, propeller shafts, valve stems, turnbuckle barrels, bolts, nuts and rivets.

### What is the chemical composition of C46400?

Copper 59.0 to 62.0 %, tin 0.50 to 1.0 %, lead 0.20 % maximum, iron 0.10 % maximum, zinc remainder. Copper plus the sum of named elements must be 99.6 % minimum. The nominal working composition is 60 % copper, 39.25 % zinc and 0.75 % tin. These limits are the same in ASTM B21, B124, B171 and B283.

### Is C46400 the same as CuZn39Sn1, CW719R or CZ112?

They are nearest equivalents rather than identical grades. The closest chemical match in the European system is CuZn39Sn1, number CW719R, which is also the ISO designation. CZ112 is the British Standard naval brass designation commonly cross-referenced to C46400, although CZ133 appears in some trade literature. CW712R / CuZn36Sn1Pb is also cited commercially but has a higher copper content and contains lead, so it is not the same alloy.

Because composition windows differ between systems, a part ordered to one designation and certified to another can fail receiving inspection. State the governing specification on the drawing and confirm the certificate wording before the order is placed.

### Is C46400 lead-free and RoHS compliant?

No lead is added to C46400 and typical heats run well below 0.10 % lead, which is why it is widely sold as lead-free naval brass. The specification permits up to 0.20 % lead maximum, which is above the 0.1 % RoHS substance threshold on paper, but RoHS Annex III exemption 6(c) covers copper alloy containing up to 4 % lead by weight, so the alloy is normally compliant by exemption. Where the actual number matters, the measured lead content appears on the EN 10204 3.1 certificate.

### Can C46400 be forged, and at what temperature?

Yes. It is one of the better-forging copper alloys, rated 90 out of 100 on the Copper Development Association forgeability scale, with capacity for hot forming rated excellent. The hot working range is 649 to 816 °C (1200 to 1500 °F). Annealing is carried out at 427 to 593 °C (800 to 1100 °F). Because machinability is only 30 % of free-cutting brass, forging close to final shape rather than machining from solid usually saves both material and machining hours.

### Is C46400 resistant to dezincification?

Partly. The tin addition makes C46400 considerably more resistant than plain 60/40 brass, but C46400 is the uninhibited grade, containing no arsenic, antimony or phosphorus. In stagnant, warm or polluted water, dezincification can still occur. Where dezincification resistance is the controlling requirement, specify C46500 (arsenical), C46600 (antimonial) or C46700 (phosphorized) instead. All four have the same mechanical and physical properties in practice.

### What is the difference between C46400, C46500, C46600 and C46700?

Only the inhibitor. C46400 has none, C46500 contains arsenic, C46600 contains antimony and C46700 contains phosphorus. Each inhibitor suppresses dezincification. Strength, density, conductivity, forgeability and machinability are unchanged between them, so the choice is a corrosion decision, not a mechanical one. If a drawing calls simply for "naval brass" and the duty is condenser cooling water, it is worth asking whether an inhibited grade was intended.

### Can C46400 be welded?

Brazing and soldering are rated excellent and are the preferred joining routes. Oxyacetylene welding is rated good, spot and butt welding good, gas shielded arc welding fair, and coated metal arc welding is not recommended. The limitation is zinc: it boils at 907 °C, barely above the alloy's liquidus, so arc processes drive zinc out of the weld pool as fume, leaving porosity and shifting the joint composition. Where a welded joint is unavoidable, agree the procedure and filler metal before the order is placed.

### Which ASTM standard covers C46400 tube sheets?

ASTM B171 / B171M, "Copper Alloy Plate and Sheet for Pressure Vessels, Condensers and Heat Exchangers", adopted by ASME as SB-171. That is the specification to quote for condenser tube plates and end plates. For forged discs and shapes where thickness or diameter goes beyond available plate, ASTM B124 / B124M covers forging rod, bar and shapes and ASTM B283 / B283M (ASME SB-283) covers hot-pressed die forgings.

### What is the largest C46400 tube sheet Jiangyin Jiangnan Metal can supply?

Machining capacity sets the limit rather than the alloy. Vertical turning lathes take up to Ø5,000 mm swing, horizontal lathes machine up to 14,000 mm between centres, and the CNC deep-hole drilling machine bores Ø1,600 × 10,000 mm. Heat-treatment furnaces accept work up to 8,000 × 2,000 × 2,000 mm. For a solid C46400 plate the practical ceiling is normally the size the copper mill can roll, which is why large or very thick tube sheets are frequently supplied as clad or weld-overlaid plate with a steel backing.

### What certification is supplied with C46400 parts?

An EN 10204 3.1 mill test certificate as standard, with EN 10204 3.2 witnessed by BV, DNV, LR, SGS, TÜV or your own inspector available on request. Positive material identification is carried out on every heat with a handheld alloy analyser, and chemical analysis is available by optical emission spectrometry to ASTM E415. The producing copper mill's certificate is supplied alongside our own documentation. The works holds CCS, BV, DNV, LR and NK classification society approvals.

### What is the minimum order quantity and lead time for C46400?

Minimum order is 10 kg with no minimum piece count, so a single part is quotable. Lead time normally runs 20 to 60 days from order confirmation, driven by copper alloy stock availability and by the amount of machining and tube-hole drilling in the part rather than by the forging operation itself. Flag witnessed inspection to EN 10204 3.2 at enquiry stage so it is built into the quoted date rather than added to it.

## 12. Data sources

Property values on this page are taken from the sources below rather than from secondary supplier listings. Where published figures disagree, the Copper Development Association value is used.

- Copper Development Association, alloy record for C46400: composition, physical properties, mechanical properties by temper, fabrication ratings and applicable specifications. https://alloys.copper.org/alloy/C46400
- ASTM B21 / B21M, Standard Specification for Naval Brass Rod, Bar and Shapes.
- ASTM B124 / B124M, Copper and Copper-Alloy Forging Rod, Bar and Shapes.
- ASTM B171 / B171M and ASME SB-171, Copper Alloy Plate and Sheet for Pressure Vessels, Condensers and Heat Exchangers.
- ASTM B283 / B283M and ASME SB-283, Copper and Copper Alloy Die Forgings (Hot Pressed).
- ASME Boiler and Pressure Vessel Code, Section II Part D: allowable stresses for copper alloys.

Property data is typical and is given for guidance; it is not a guarantee of the properties of any particular delivery. Purchase requirements are set by the governing specification stated on the order.

## Related grades

Monel 400, Monel K-500, Incoloy 825, Alloy 20, Inconel 625, 316L / S31603, SAF 2205 duplex, SAF 2507 super duplex, 254 SMO, AL-6XN, 904L. Full grade index: https://www.steelforgepieces.com/#materials

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Published by Jiangyin Jiangnan Metal Co., Ltd., steelforgepieces.com. This page may be quoted with attribution.