Gun Metal Flanges: Complete Technical Guide by Creative Piping Solutions Pvt. Ltd.
Gun Metal—also known as Red Brass, RG5, C83600, or Copper Tin Zinc Alloy—has been one of the most reliable and corrosion-resistant alloys used in piping systems for decades. At Creative Piping Solutions Pvt. Ltd., we manufacture and export high-precision Gun Metal Flanges engineered for superior performance in marine, engineering, steam, and hydraulic applications.
This in-depth guide covers material composition, mechanical properties, manufacturing standards, applications, advantages, types of flanges, pressure ratings, installation guidelines, and inspection methods—everything required to understand Gun Metal Flanges from a technical point of view.
What Are Gun Metal Flanges?
Gun Metal Flanges are copper-based alloy flanges primarily composed of:
- Copper (Cu): 85–88%
- Tin (Sn): 5–8%
- Zinc (Zn): 3–5%
- Lead (Pb): 2–5% (for machinability)
Gun Metal flanges are widely used in water supply systems, marine engineering, pump industries, shipbuilding, valves, and hydraulic lines because they exhibit:
- Excellent corrosion resistance against seawater and brine.
- High pressure-handling capacity.
- Superior casting properties.
- Great machinability and thermal stability.
ASME B16.5 — Slip-On Flange, Class 150 — common sizes ½″ → 12″
| NPS (in) | Bore D1 / B (in) | Outside Dia D (in) | Flange Thk t (in) | Raised Face Dia R (in) | Bolt Circle Dia K (in) | No. of Bolts × Bolt Dia n-d (in) | Approx Weight (kg) |
|---|---|---|---|---|---|---|---|
| 1/2 | 0.840 | 3.50 | 0.44 | 1.88 | 2.75 | 4-0.50 | 0.30 |
| 3/4 | 1.050 | 3.87 | 0.44 | 2.12 | 3.12 | 4-0.50 | 0.36 |
| 1 | 1.315 | 4.50 | 0.56 | 2.44 | 3.50 | 4-0.63 | 0.55 |
| 1-1/4 | 1.660 | 5.00 | 0.56 | 2.88 | 3.88 | 4-0.63 | 0.72 |
| 1-1/2 | 1.900 | 5.50 | 0.56 | 3.12 | 4.38 | 4-0.75 | 0.95 |
| 2 | 2.375 | 6.50 | 0.62 | 3.62 | 4.88 | 4-0.75 | 1.45 |
| 2-1/2 | 2.875 | 7.50 | 0.75 | 4.38 | 5.75 | 4-0.88 | 1.95 |
| 3 | 3.500 | 8.00 | 0.75 | 4.75 | 6.25 | 6-0.75 | 2.80 |
| 4 | 4.500 | 9.00 | 0.88 | 5.75 | 7.50 | 8-0.75 | 4.50 |
| 6 | 6.625 | 11.00 | 1.06 | 7.75 | 9.88 | 8-0.75 | 9.20 |
| 8 | 8.625 | 13.00 | 1.25 | 10.00 | 12.00 | 8-0.88 | 17.5 |
| 10 | 10.750 | 15.00 | 1.31 | 11.25 | 14.00 | 12-0.88 | 27.0 |
| 12 | 12.750 | 17.00 | 1.50 | 13.00 | 16.00 | 12-0.88 | 36.5 |
Chemical Composition of Standard Gun Metal (Typical RG5 / C83600)
| Element | % Composition |
|---|---|
| Copper (Cu) | 84.0–88.0% |
| Tin (Sn) | 5.0–8.0% |
| Zinc (Zn) | 3.0–5.0% |
| Lead (Pb) | 2.0–5.0% |
| Nickel (Ni) | ≤ 1.0% |
| Iron (Fe) | ≤ 0.3% |
Mechanical Properties of Gun Metal Flanges
| Property | Value |
|---|---|
| Tensile Strength | 210–260 MPa |
| Yield Strength | 90–120 MPa |
| Elongation | 12–18% |
| Brinell Hardness | 65–80 HB |
| Melting Point | 850–950°C |
| Density | 8.7–8.9 g/cm³ |
These mechanical characteristics ensure durability even in the harshest operating conditions.
Manufacturing Standards Followed by Creative Piping Solutions
Gun Metal Flanges can be manufactured according to multiple global standards:
- ASME B16.5
- ASME B16.47
- BS 4504
- DIN / EN 1092-1
- ISO Standards
- JIS 5K, 10K, 16K
- AWWA Standards (Water Supply Applications)
We offer customization for size, schedule, pressure rating, drilling patterns, and face finish.
Types of Gun Metal Flanges Manufactured
Gun Metal can be cast or machined into almost all standard flange types:
Gun Metal Slip-On Flanges (SO)
- Easy alignment and installation.
- Suitable for low-to-medium pressure lines.
Gun Metal Weld Neck Flanges (WN)
- Best for high-pressure, high-temperature systems.
- Smooth stress distribution.
Gun Metal Threaded Flanges
- Ideal for small-size pipelines without welding.
- Perfect for water, gas, and oil applications.
Gun Metal Blind Flanges
- Used for closing ends of piping systems or pressure vessels.
Gun Metal Lap Joint Flanges
- Used with stub ends for frequently dismantled pipelines.
Gun Metal Socket Weld Flanges
- Suitable for small-bore lines with high pressure.
Gun Metal Companion Flanges / Pump Flanges
- Commonly used in pump installations and waterworks.
Custom CNC-Machined Gun Metal Flanges
- As per drawing and engineering requirements.
Pressure Ratings Available
Gun Metal Flanges are offered in:
- PN6
- PN10
- PN16
- PN25
- PN40
- Class 150
- Class 300
Special high-pressure variants available upon request.
Advantages of Gun Metal Flanges
Superior Corrosion Resistance
- Resists saltwater, chemicals, brine, sewage, and steam.
Excellent Castability
- Allows precise manufacturing of complex shapes.
High Dimensional Stability
- Stable under varying thermal and mechanical loads.
Long Service Life
- Extensive lifespan in marine and pump systems.
Great Machinability
- Ideal for precision machining and tight-tolerance requirements.
Leak-Free Joint Integrity
- Flange surface finish ensures reliable sealing.
Industrial Applications of Gun Metal Flanges
Gun Metal Flanges are widely used in:
Marine & Offshore
- Shipbuilding
- Sea-water lines
- Ballast systems
- Marine pumps and valves
Water Supply & Plumbing
- Freshwater transmission
- Sewage systems
- Pump casings
Oil & Gas (low pressure)
- Lubrication systems
- Fuel lines
Hydraulic & Pneumatic
- Compressor lines
- Hydraulic manifolds
Engineering & Manufacturing
- Heavy machinery
- Cooling systems
- Heat exchangers
Fire Fighting & Sprinkler Systems
- Gun metal is widely preferred for corrosion-free long-term installation.
Gun Metal vs Bronze vs Brass Flanges
| Property | Gun Metal | Bronze | Brass |
|---|---|---|---|
| Composition | Cu-Sn-Zn | Cu-Sn | Cu-Zn |
| Corrosion Resistance | Excellent | Very Good | Good |
| Strength | Medium | High | Medium |
| Cost | Moderate | Higher | Lower |
| Applications | Marine, Water | Heavy-duty | Plumbing |
Gun Metal provides the best balance of price, corrosion resistance, and machinability.
Technical Features Required in High-Quality Gun Metal Flanges
Creative Piping Solutions ensures:
- Accurate bolt hole alignment
- Smooth surface finish (Ra 3.2–6.3 µm)
- Stable casting with defect-free structure
- Correct flange facing (RF/FF)
- Uniform grain structure
- Pressure-tested and leak-tested finish
Inspection & Testing Performed
To ensure 100% reliability, we conduct:
- Chemical composition analysis
- Tensile & hardness test
- Dimensional inspection
- Hydro test
- Pneumatic test
- Visual inspection
- Microstructure analysis
- NDT (if required)
Test certificates are provided based on customer requirements.
Export Capabilities of Creative Piping Solutions
We export Gun Metal Flanges to:
- Middle East: United Arab Emirates, Saudi Arabia, Oman, Qatar, Kuwait, Bahrain, Iraq, Iran, Jordan, Lebanon, Israel, Yemen.
- India–Surrounded Countries: Sri Lanka, Nepal, Maldives, Bangladesh, Bhutan, Myanmar, etc.
- ASEAN: Indonesia, Malaysia, Singapore, Thailand, Vietnam, Philippines, Brunei Darussalam, Cambodia, Laos.
- Europe: United Kingdom, Germany, France, Italy, Spain, Netherlands, Poland, Russia, Norway, Sweden.
- Africa: South Africa, Egypt, Nigeria, Morocco, Kenya, Algeria, Ghana, Tanzania, Ethiopia, Uganda, Tunisia, Libya, Sudan.
- North & South America: United States, Canada, Mexico, Brazil, Argentina, Chile, Colombia, Peru, etc.
Customized packaging is provided for safe international logistics.
Why Choose Creative Piping Solutions Pvt. Ltd. for Gun Metal Flanges?
- State-of-the-art casting and CNC machining
- On-time delivery with export-grade packing
- Wide size range from ½” to 48”
- Strict quality control and ISO-certified processes
- Competitive pricing for global clients
- Custom drawings and OEM production available
We ensure precision, durability, and long-term performance in every flange we manufacture.
Conclusion:
Gun Metal Flanges are a reliable choice for industries that demand high corrosion resistance, long service life, and superior machinability. With years of manufacturing excellence, Creative Piping Solutions Pvt. Ltd. stands as a trusted supplier and exporter of premium-quality Gun Metal Flanges.
CONTACT CREATIVE PIPING SOLUTIONS NOW
For Quotes & Technical Inquiries:
- Email: sales@creativeforged.com
- Phone: +91 7045 212 326