Copper hexagonal connectors, precise marine hardware for ships, CNC machining services

Application and Characteristics of Brass Hexagonal Fittings in Shipbuilding Industry

with Focus on Machining Features

1. Application Scenarios in Shipbuilding Industry

(1) Pipeline Systems (Core Application)

• Seawater / Freshwater Systems: Connections and branches for cooling pipelines, fire water pipes, ballast water pipes, and domestic water pipes, complying with marine standards such as CB/T 4328-2013.
• Fuel / Lubricating Oil Systems: Fuel delivery and lubricating oil circulation pipeline connections, oil-resistant and leak-proof.
• Compressed Air / Pneumatic Systems: Pipelines for deck pneumatic tools and pneumatic valve control; hexagonal structure facilitates wrench operation.
• Hydraulic Systems: Low-pressure hydraulic pipeline connections for deck machinery (windlasses, winches) and steering gears.

(2) Deck and Outfitting Equipment

• Fastening and pipeline adapters for mooring equipment, railings, hatch covers, vents, portholes, etc.
• Mounting joints for navigation / communication equipment bases, lamps, and signal devices.

(3) Instrument and Electrical Systems

• Instrument connectors for pressure gauges, thermometers, and level gauges. Brass is conductive, non-sparking, and anti-interference.
• Pipeline penetration and sealing joints for marine electrical boxes, junction boxes, and explosion-proof areas.

(4) Special Scenarios

• Explosion-proof / Non-sparking Areas: Pipeline connections in cargo pump rooms, LNG carriers, and chemical tankers. Brass does not produce sparks upon impact or friction.
• Seawater / Salt Spray Environment: Long-term resistance to chloride ion corrosion, with service life 5–10 times longer than ordinary carbon steel.

2. Key Characteristics in Marine Applications

(1) Material Performance Advantages

• Seawater / Salt Spray Corrosion Resistance: Forms a dense oxide film to resist chloride ion erosion. Naval brass (e.g., CW712R, HAl77-2) is more suitable for harsh marine environments.
• Non-sparking Safety: Non-ferrous metal, meeting marine explosion-proof requirements.
• Mechanical Adaptability: Moderate strength, good toughness, resistant to vibration and shock under navigation conditions.
• Anti-seizing Property: Thread connections are not prone to sticking, easy for maintenance and disassembly.

(2) Structural and Installation Features

• Hexagonal Shape: Stable clamping with wrenches, good torque transmission, suitable for installation in narrow cabins.
• Reliable Sealing: High-precision machined threads, matched with gaskets or PTFE tape, meeting marine pipeline pressure resistance (PN16–PN100) and anti-leakage requirements.
• Standardization: Compliant with CB/T, ISO, JIS and other marine standards, with strong interchangeability.

3. Core Characteristics of Machined Brass Hexagonal Fittings

(1) Excellent Machinability

• Free-cutting: Commonly used free-cutting brass such as HPb59-1 and C3604, with low cutting resistance and long tool life.
• High Efficiency: Cutting speed can reach 200–300 m/min, much higher than steel, suitable for mass and automated production.
• Smooth Chip Removal: Small and brittle chips, not easy to wrap around tools, ideal for CNC and automatic lathes.

(2) High Precision and Surface Quality

• High Dimensional Accuracy: Up to IT7–IT8 grade; thread accuracy (G, NPT, UNF) meets marine sealing and assembly requirements.
• Good Surface Finish: Ra ≤ 1.6 μm, reducing fluid resistance and corrosion risks.
• Burr-free & Defect-free: Easy deburring and chamfering, improving assembly and sealing reliability.

(3) Strong Process Adaptability

• Flexible Processes: Turning, milling, drilling, tapping, knurling can be completed in one or multiple clampings, suitable for complex structured fittings.
• Controllable Thermal Deformation: Brass has high thermal conductivity; high-pressure cooling and roughing-finishing separation ensure dimensional stability.
• Suitable for Small-batch / Customization: Quick changeover on CNC machines, matching the multi-specification, small-batch demand in shipbuilding.

(4) Key Control Points for Marine Machining

• Tool Selection: Carbide tools with sharp edges to reduce adhesion and built-up edge.
• Cooling and Lubrication: Emulsion or special cutting fluid to lower temperature and improve surface quality.
• Clamping and Anti-deformation: Soft jaws and multi-point support to avoid deformation of hexagonal surfaces and thin walls.
• Stress Relief and Cleaning: Stress relief and ultrasonic cleaning after machining to ensure no residue or stress cracks.

4. Summary of Selection and Machining

• Common Grades: HPb59-1, H62, CW712R (Naval Brass), C3604.
• Machining Advantages: High efficiency, high precision, excellent surface quality, strong consistency, meeting the reliability and standardization requirements of marine fittings.
• Application Limits: For high pressure (>10 MPa), cryogenic, and strong chemical corrosion environments, stainless steel or special alloys are preferred.

We have introduced advanced equipment and technology from Japan and Germany (CNC 5-axis and 6-axis machines) to better serve our customers' needs.

Our maximum processing outer diameter is 60, and the minimum control tolerance is 0.001. We have Japanese CNC Tsugami, CNC Citizen, multi-station cold extrusion forming machines, 500T press machines, casting equipment, and various process equipment, which can effectively provide customers with the best technical solutions.

Our company has a total of 300 employees, including 20 technicians, 10 engineers, and 15 quality control personnel. We have over 300 pieces of equipment.

Our company implements 8S management and has passed ISO9001 and TS16949 automotive certifications.

Our customers include Siemens, bo-sch, Foxconn, Panasonic Motors, Husqvarna, Shimano, NVIDIA, DJI Drones, Siegenia, and Cater-pillar.