ASTM B283 C37700 Fittings – Forging Brass Die Forgings
What is ASTM B283? ASTM B283 (ASME SB283) is the standard specification for copper and copper-alloy die forgings (hot-pressed). UNS C37700 – known as forging brass – is the most widely used alloy under it: about 60% copper, 2% lead and the rest zinc. It has the best hot-forgeability of all copper alloys and good machinability, which makes it the standard material for forged valve bodies and pipe fittings.
ASC LLP supplies ASTM B283 C37700 forged fittings – elbows, tees, couplings, unions, nipples, plugs, caps and valve bodies – with EN 10204 3.1 certificates. See our full copper alloy fittings range.
C37700 Chemical Composition (ASTM B283)
| Element | Composition (wt %) |
| Copper (Cu) | 58.0 – 61.0 |
| Lead (Pb) | 1.5 – 2.5 |
| Iron (Fe) | 0.30 max |
| Zinc (Zn) | Remainder |
| Cu + named elements | 99.5 min |
The roughly 40% zinc gives C37700 a two-phase (alpha-beta) structure that flows easily when hot – the reason it is the reference alloy for hot forging (forgeability rating 100). The lead improves machinability.
Key Properties & Advantages of C37700 Fittings
- Best hot-forgeability of all copper alloys: complex, near-net-shape fittings and valve bodies can be die-forged in one press stroke.
- Good machinability (rating 80): fast threading and drilling after forging.
- Dense, pressure-tight forgings: forged structure is free of the porosity found in some castings.
- Good strength: typically about 360 MPa tensile as forged.
- Corrosion resistance: good in fresh water, air, refrigerants, fuel gases and many neutral fluids.
- Easy to join: excellent for soldering and good for brazing; threaded ends are most common.
Not recommended for seawater or water that causes dezincification – use a dezincification-resistant brass, bronze or copper-nickel for those services.
C37700 Forged Fitting Types & Sizes
| Item | Details |
| Fitting types | Elbows, tees, crosses, couplings, unions, reducers, nipples, plugs, caps, bushings, valve bodies |
| End connections | Threaded (NPT / BSP), compression, flare, solder |
| Sizes | 1/8″ to 4″ typical; larger forgings on request |
| Pressure class | As per design / customer drawing |
| Production | Hot die forged (pressed), then machined |
| Finish | Natural, sand-blasted, nickel or chrome plated on request |
Mechanical Properties of C37700
| Property | Typical value |
| Tensile strength | ≈ 360 MPa (52 ksi) |
| Yield strength (0.5% ext.) | ≈ 140 MPa (20 ksi) |
| Elongation | ≈ 45% |
| Hardness | ≈ 78 HRF |
Typical values (hot-worked condition, Copper Development Association). Actual values depend on section size and forging practice.
ASTM B283 C37700 Specifications
| Standard | Covers |
| ASTM B283 / ASME SB283 | Copper and copper-alloy die forgings (hot-pressed) |
| ASTM B124 | Copper-alloy forging rod, bar and shapes |
| AMS 4614 | Brass forgings, as forged |
| SAE J461 / J463 | Wrought and cast copper alloys |
| Test certificate | EN 10204 3.1; third-party inspection on request |
C37700 Equivalent Grades
| Standard | Nearest equivalent |
| UNS | C37700 |
| Common name | Forging brass, hot-stamping brass |
| EN 12420 / 12164 | CW617N (CuZn40Pb2), CW612N (CuZn39Pb2) |
| JIS H3250 | C3771 |
| BS 2872 (old) | CZ122 |
Equivalents are close but not identical – check chemistry limits before substituting.
Physical Properties of C37700
| Property | Value (approx.) |
| Density | 8.44 g/cm³ (0.305 lb/in³) |
| Melting range | 882 – 893 °C (1,620 – 1,640 °F) |
| Thermal conductivity | ≈ 119 W/m·K |
| Electrical conductivity | 27% IACS |
| Coefficient of thermal expansion | ≈ 20.7 µm/m·°C (20–300 °C) |
| Modulus of elasticity | ≈ 103 GPa (15 × 10⁶ psi) |
| Hot-working range | 650 – 815 °C |
Applications of ASTM B283 C37700 Fittings
| Industry | Typical uses |
| Plumbing & water | Forged fittings, valve bodies and stop valves for fresh-water lines |
| Gas & LPG | Gas valves, regulators, cylinder valves and fittings |
| HVAC & refrigeration | Refrigeration valves, flare and compression fittings |
| Industrial & agricultural | Valves and fittings for chemicals, spray tanks and compressed air |
| Hardware | Door handles, knobs and decorative builders’ hardware |
Why Buy ASTM B283 C37700 Fittings from ASC LLP?
- Certified material: ASTM B283 / ASME SB283 forgings with EN 10204 3.1 certificates.
- Full range: standard fittings and custom forgings to your drawing.
- Related products: ASTM B62 C83600 bronze fittings, ASTM B124 C46400 naval brass fittings, copper alloy flanges and other copper alloys.
- Inspection: PMI, dimensional and pressure testing, third-party inspection on request.
- Export packing and worldwide delivery.
Send your fitting type, size, end connection and quantity to sales@amardeepsteel.com or call 022-67439130.
Frequently Asked Questions – ASTM B283 C37700
What is ASTM B283?
ASTM B283 (ASME SB283) is the standard specification for copper and copper-alloy die forgings made by hot pressing. It covers alloys such as C37700 forging brass, C46400 naval brass and others used for forged fittings and valve bodies.
What is the chemical composition of C37700?
C37700 contains 58.0–61.0% copper, 1.5–2.5% lead, 0.30% max iron and the remainder zinc, with copper plus named elements at least 99.5%.
Is C37700 brass or bronze?
C37700 is a brass – a copper-zinc alloy with a small lead addition. It is commonly called forging brass.
What is the difference between C37700 and C36000?
C37700 is forging brass, optimised for hot die forging. C36000 is free-cutting brass, optimised for high-speed machining of rod. Both are leaded brasses but with different copper and lead contents.
What is the European equivalent of C37700?
The closest European grades are CW617N (CuZn40Pb2) and CW612N (CuZn39Pb2). JIS C3771 is the Japanese equivalent.
Can C37700 fittings be used in seawater?
It is not recommended. Leaded alpha-beta brasses can dezincify in seawater and some waters; bronze, dezincification-resistant brass or copper-nickel fittings are better choices.
Global Reach
ASC LLP supplies copper-alloy fittings, valves and flanges to plumbing, gas, HVAC and industrial customers worldwide, with prompt delivery and full documentation. Buyers in the USA, Europe, the Middle East and Asia rely on our ASTM B283 C37700 fittings for certified material and traceability.
Countries We Export To
UNITED STATES, EUROPE, UK, UAE, SAUDI ARABIA, OMAN, KUWAIT, JORDAN, QATAR, INDONESIA, MALAYSIA, BRAZIL, SPAIN, ITALY, FRANCE, GERMANY, BAHRAIN, SRI LANKA, AZERBAIJAN, AUSTRALIA, AUSTRIA, PHILIPPINES, TURKEY, RUSSIA, IRAN, IRAQ, CANADA, KOREA, JAPAN, YEMEN, FINLAND, ZIMBABWE, HUNGARY, PORTUGAL, VIETNAM, MOROCCO, THAILAND, SOUTH AFRICA, MEXICO, SINGAPORE, GREECE, KUWAIT, POLAND, NEW ZEALAND, SWEDEN, SWITZERLAND, BELGIUM, BHUTAN, BANGLADESH, TAIWAN, ROMANIA, CAMBODIA, KAZAKHSTAN, AFGHANISTAN.
