Admiralty brass is a copper-zinc alloy with small additions of tin and arsenic - the arsenic being added deliberately to inhibit dezincification corrosion. Its classic designation is C44300 (ASTM / UNS), with European designation CuZn28Sn1 (EN 12451). Admiralty brass tube is the long-standing default specification for steam condenser tubing and heat-exchanger service in marine, power and process industries, and this page sets out the material data, standards and sizes you need to specify it correctly.
Key Takeaways
- Admiralty brass C44300 = Cu 70–73%, Sn 0.9–1.2%, As 0.02–0.06%, balance zinc; the arsenic inhibits dezincification.
- Governing standards: ASTM B111 / ASME SB-111 (C44300), BS 2871 Part 3 CZ111, EN 12451 CuZn28Sn1As, JIS H3300 C4430.
- It offers the best resistance of the common brasses to sulphur compounds and contaminated water, at a lower cost than cupronickel.
- Typical applications: steam condenser tubes, feedwater heaters, refinery heat exchangers, marine and brackish-water service.
What Is Admiralty Brass?
Admiralty brass is a 70/30-type brass (approximately 70% copper, 30% zinc) modified with about 1% tin and a controlled arsenic addition of 0.02–0.06%. The tin improves corrosion resistance in sulphur-bearing and polluted waters; the arsenic suppresses dezincification, the selective leaching of zinc that weakens ordinary brass in seawater and brackish service. This combination makes admiralty brass markedly more durable than plain 70/30 brass in aggressive environments while remaining more economical than cupronickel alloys.
Governing Standards and Equivalents
Admiralty brass tube is produced seamless to the following standards:
- ASTM B111 / ASME SB-111 - C44300, the internationally dominant condenser-tube specification.
- BS 2871 Part 3 - CZ111 (UK).
- EN 12451 - CuZn28Sn1As (Europe).
- JIS H3300 - C4430 (Japan).
- DIN 1785 - CuZn28Sn1 (Germany).
Chemical Composition (Mass Fraction, %)
| Element | ASTM B111 C44300 | EN 12451 CuZn28Sn1As |
|---|---|---|
| Copper (Cu) | 70.0 – 73.0 | 70.0 – 72.5 |
| Tin (Sn) | 0.9 – 1.2 | 0.9 – 1.3 |
| Arsenic (As) | 0.02 – 0.06 | 0.02 – 0.035 |
| Iron (Fe), max | 0.06 | 0.07 |
| Lead (Pb), max | 0.07 | 0.07 |
| Zinc (Zn) | Remainder | Remainder |
Exact limits are defined in the governing standard; the mill test certificate supplied with each shipment states the measured values.
Mechanical and Physical Properties
Typical tensile properties for annealed (O) and light-drawn tempers of C44300 tube:
- Tensile strength: 310 MPa minimum (ASTM B111, annealed condition).
- Elongation: 45% minimum in 50 mm for annealed tube.
- Hardness (Rockwell F, annealed): approximately 75 HRF maximum.
- Good ductility and formability, permitting rolling-in and flaring in condenser tube sheets.
The combination of good thermal conductivity, ductility and corrosion resistance is why admiralty brass has remained a standard condenser material for over a century.
Corrosion Resistance and Application Environments
Admiralty brass is selected where the cooling water is aggressive but not highly saline:
- Steam condensers and surface condensers (power generation and marine propulsion).
- Feedwater heaters and oil coolers.
- Heat exchangers in refineries, petrochemical and process plants.
- Service with seawater, brackish water, polluted river water and sulphur-compound-bearing water.
Where cooling water is severely saline or chlorinated, cupronickel (e.g. C70600 / C71500) is the preferred upgrade; admiralty brass remains the economical first choice for moderate environments.
Available Sizes and Tempers
Gnee supplies seamless admiralty brass tube in the following range:
- Outer diameter: 4 mm – 150 mm.
- Wall thickness: 0.25 mm – 8 mm.
- Length: 1 m, 2 m, 3 m, 4 m, 6 m, or cut length to drawing.
- Forms: round, square and rectangular; seamless.
- Tempers: annealed (O), temper-annealed (TA) and as-manufactured (M) to ASTM B111.
FAQ
What is the difference between admiralty brass and aluminium brass?
Admiralty brass (C44300) adds ~1% tin + arsenic; aluminium brass (C68700) adds ~2% aluminium + arsenic. Aluminium brass offers higher strength and better erosion resistance in high-velocity seawater, while admiralty brass is preferred for moderate, sulphur-bearing waters.
Why is arsenic added to admiralty brass?
Arsenic (0.02–0.06%) is a deliberate dezincification inhibitor. Without it, zinc leaches selectively from the alloy in seawater and brackish water, leaving a weak porous copper layer.
Which standard is used for condenser tubes worldwide?
ASTM B111 (with the ASME SB-111 code version) is the dominant international specification for seamless condenser and heat-exchanger tubes, including C44300 admiralty brass.
Can admiralty brass tube be used for potable water plumbing?
Admiralty brass is engineered for heat-exchanger service, not potable-water distribution. For plumbing, use standard copper tube to ASTM B88 or brass fittings compliant with local potable-water regulations.
References
- ASTM B111 / ASME SB-111 - Standard Specification for Copper and Copper-Alloy Seamless Condenser Tubes and Ferrule Stock.
- BS 2871 Part 3 - Specification for copper and copper alloy tubes: tubes for heat exchangers (CZ111).
- EN 12451 - Copper and copper alloys: Seamless, round tubes for heat exchangers (CuZn28Sn1As).
- JIS H3300 - Copper and copper alloy seamless pipes and tubes (C4430).
- DIN 1785 - Tubes of copper-zinc alloys for surface condensers and heat exchangers.
Copper products that GNEE can provide
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Product Name |
Straight Copper Pipe/Pancake Coil Copper Pipe/Capillary copper pipe |
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Material |
C10100,C10200,C12000,C12200,C11000,T1,T2,T3,TP2,TU1,TU2,TU3,H62, H65,H70,etc |
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Standard |
ASTM B280,ASTM B68,ASTM B75,ASTM B88 JIS H3300 EN12735,AS1571 |
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Shape Type |
Straight Round,Square,Rectangular,Coil,Oval,Half-Round |
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Wall Thickness |
0.2-3mm |
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Out Diameter |
3mm-100mm |
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Length |
1M-6M or As your demand (Pancake copper tube usual length: 15 meters) |
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Cu |
High Purity 99.9% Copper |
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Temper |
Soft(M),Half Soft(M2) and Half Hard(Y2) |
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Surface Treatment |
Bright and Clean |
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Package Type |
Plastic Film With Plastic Caps on the both ends and Wooden Case Carton Package or as your demand |
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Application |
Refrigerator,Condenser and Heat Exchange,Decoration,Water Tube,Precision Equipment etc |
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Item |
Straight copper rod/copper round bar |
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Standard |
ASTM,DIN,BS,CDA,JIS,GB |
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Material |
T1,T2,C10100,C10200,C10300,C10400,C10500,C10700,C10800, |
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Shape |
Round,Square,Rectangular,etc. |
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Specifications |
Diameter:3~200mm |
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Length |
3m,5.8m, 6m, 11.8m, 12m, or as required. |
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Hardness |
1/16 hard,1/8 hard,3/8 hard,1/4 hard,1/2hard,full hard,soft,etc |
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Surface |
mill,polished,bright,oiled,hair line,brush,mirror,sand blast,or as required. |
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Price term |
EXW, FOB, CFR, CIF, etc. |
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Payment term |
T/T |
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Package |
Export standard package: bundled wooden box, suit for all kinds of transport, |
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Delivery time |
According to order quantity |
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Application |
A copper rod is a type of colored metal processing bar stock with high electrical conductivity. It is mainly divided into brass |
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Contact |
If any requirement please feel free to inform me at any time. |
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Size |
Width: 10mm to 2000mm, |
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Hardness |
1/16 hard,1/8 hard,3/8 hard,1/4 hard,1/2hard,full hard. |
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Surface |
Polished,bright,oiled,hair line,brush,mirror,or as required |
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Export to |
Ireland,Singapore,Indonesia,Ukraine,Saudi Arabia,Spain,Canada,USA, |
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Package |
Plastic film with Wooden case or wooden pallet |
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Delivery time |
Prompt delivery or upon your order quantity. |
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Quality Control |
Mill Test Certification is supplied with shipment,Third Part Inspection is acceptable. |
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Application |
widely used inair conditioners,refrigerators,electric,solar water heater, polished pipe an be used in decorative,such as stair rail. |
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Shape |
Round, Square, Oval, can be customized |
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Model Number |
C11000, C10200, C12000, C12200 C26800 C27000 C35000 C38000 etc. |
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Color |
Red Cppper , Brass |
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Hardness |
1/16 hard, 1/8 hard, 3/8 hard, 1/4 hard, 1/2hard, full hard, soft, etc |
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Diameter |
0.10mm-5.00mm |
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Insulation Material |
Enameled |
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Certification |
ISO9001 |
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Advantages |
High conductivity,Good solderability,High ductility |
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Coating |
Double Layer or customized |
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Packing |
Standard export package or seaworthy Package |
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Application |
1. Pancake Coil for ACR, General Engineering Applications |
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copper CNC machined parts
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Precision of piece: |
+/-0.01mm |
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Roughness of piece: |
Ra≤0.1 |
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Quality standard: |
DIN, ASTM, GOST, GB, JIS, ANSI, BS; |
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Drawing format: |
JPEG,PDF,AI,PSD,DWG,DXF,IGS,STEP; |
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Products certification: |
ISO9001:2008, CE, RoHS, SGS; |
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Dimension: |
Dia.500mm or 850mm width |
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Available materials |
Steel: carbon steel, alloy steel, stainless steel, 4140,20#,45# ,40Cr,20Cr ,etc |
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Aluminum: AL6061,AL6063,AL6082,AL7075,AL5052 etc. |
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Stainless steel: 201SS,301SS,304SS,316SS etc. |
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Brass: C37700,C28000, C11000,C36000 etc |
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Plastics: PTFE,PEEK,POM,PA,UHMW, NYLON |
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Surface treatment: |
Steel parts |
Stainless steel parts |
Aluminum parts |
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Galvanization |
Polishing |
anodized |
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Black oxidation |
Passivation |
Sandblast anodized |
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Nickel plating |
Laser engraving |
Colorful anodized |
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Chrome plating |
Sand blast |
Brushed |
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Heat treatment |
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Polishing |
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Powder coated |
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Chrome plating |
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Why choose us?
Since our establishment in 2008, our company has specialized in the production and export of copper products. We utilize advanced production lines and a comprehensive quality control system. From raw materials to finished products, every step is rigorously inspected using precision instruments (such as spectrometers, metallographic microscopes, and conductivity testers) to ensure that our products meet international standards for composition, dimensions, and performance. We are committed to providing high-quality, high-precision copper products and reliable service to our global customers.
Email:sales@gneesteel.com
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