Client Background
In Q3 2025, we received an inquiry from a Karachi-based marine engineering contractor involved in the refurbishment of seawater pipeline systems for a local shipyard project.
The client had previously sourced brass materials locally but faced:
Premature corrosion issues
Inconsistent material composition
Lack of proper certification
They were specifically looking for a reliable overseas supplier who could meet EN / ASTM standards with full traceability.
Initial Inquiry Details
The first RFQ included very clear technical requirements:
Material: CW712R / C46400 Naval Brass
Diameter: 3.125" (79.375 mm)
Total Length: 130 meters
Estimated Weight: ~6 tons
Application: Seawater valve and shaft components
Client Concern
The client emphasized:
"Previous materials failed due to low tin content and internal porosity."
This is a very typical real-world issue in marine brass sourcing, especially from low-quality suppliers.
Our Engineering Evaluation
After reviewing the inquiry, our technical team identified two critical control points:
1. Tin (Sn) Content Stability
We adjusted melting parameters to strictly control:
Sn: 0.95% – 1.05% (tight range instead of wide spec)
This ensured:
Stable corrosion resistance
Improved lifespan in seawater
2. Internal Structure Control
For large-diameter rods (79.375 mm), we implemented:
Controlled hot extrusion ratio
Slower cooling process
This reduced:
Internal porosity
Segregation defects
Production & Quality Records
Production Batch No.: NB2025-08-KHI
Melting Furnace: 8-ton induction furnace
Total Produced: 6.35 MT (including cutting allowance)
| Test Item | Result |
|---|---|
| Tensile Strength | 415 MPa |
| Elongation | 18% |
| Hardness | HB 110 |
| Ultrasonic टेस्ट | No internal defects |
| Chemical Sn | 0.98% |
All results were documented in:
EN 10204 3.1 Mill Test Certificate
Internal inspection reports
Packaging & Shipment
We packed the rods in:
Fumigated wooden crates
Internal plastic + anti-moisture wrapping
Steel strapping reinforcement
Shipping Details
Port of Loading: Shanghai
Destination: Karachi Port, Pakistan
Incoterm: C&F (Incoterms 2020)
Container: 1 × 20GP
Timeline
Production: 17 days
Customs & loading: 3 days
Sea transit: 24 days
✔ Total delivery cycle: 44 days
On-Site Feedback
After installation, the client provided feedback:
Machining performance: Smooth, no cracking
Dimensional accuracy: Within tolerance
Surface condition: Clean, no oxidation
Most importantly:
"Material passed pressure and corrosion testing without any issue."
Application Scenario
The supplied rods were used in:
Seawater valve stems
Marine shaft components
Pump connection parts
These are high-risk environments, requiring:
Anti-dezincification properties
Long-term corrosion resistance
FAQ
1. What causes naval brass failure in marine environments?
Low tin content and internal defects can lead to rapid corrosion and structural failure.
2. How do you ensure quality for C46400 rods?
We control chemical composition, perform ultrasonic testing, and provide EN 10204 3.1 certification.
3. Can you supply large diameter naval brass rods?
Yes, we can produce up to 200 mm diameter with stable internal structure.
4. What is the delivery time to Pakistan?
Typically 40–45 days including production and shipping.
Contact Us
If you are sourcing CW712R / C46400 Naval Brass Rods for marine or industrial use:
We can help you avoid the same issues this client faced.
📩 Send your RFQ today for:
Fast quotation
Technical support
Stable quality supply
