C3604 Brass Alloy: Uses, Properties & Our Processing Capabilities

author: YITECH

2025-10-14

Table of Contents

What Is C3604 Brass Alloy?
Key Properties of C3604 Brass
Main Applications of C3604 Brass
Our Company's C3604 Processing Capabilities
C3604 vs. Other Metals/Brass Alloys: Comparison Table
Expert Opinion on C3604 Brass
FAQ About C3604 Brass Processing

1. What Is C3604 Brass Alloy?

C3604 brass is a type of free-cutting brass alloy (also called “leaded brass”). It is one of the most widely used brass grades for machining. Its main components are:

Copper (Cu): 60–63% (gives brass its strength and corrosion resistance)
Zinc (Zn): 33–37% (lowers melting point and improves machinability)
Lead (Pb): 2.5–3.7% (the key “free-cutting” element—reduces friction during machining)

C3604 is not a random mix. The lead content makes it easy to cut, drill, and shape. This is why it is the top choice for mass-producing small, precise parts. Unlike pure copper (which is hard to machine) or low-lead brass (which wears tools quickly), C3604 balances performance and cost.

2. Key Properties of C3604 Brass

C3604's popularity comes from its 4 core properties. These make it ideal for industrial manufacturing:

1. Excellent Machinability

The lead in C3604 acts as a “lubricant” during cutting. It reduces friction between the tool and the brass. This means:

Tools last 2–3 times longer than when machining pure copper.
Machines can run faster (up to 3,000 RPM for CNC lathes).
Fewer defects (like rough surfaces or broken parts) during production.

2. Good Mechanical Strength

C3604 is strong enough for daily use. Its tensile strength (ability to resist breaking under pressure) is 300–350 MPa. This is higher than low-lead brass (C3600: 280–320 MPa). It can handle small loads—like the pressure on a nut or a connector.

3. Moderate Corrosion Resistance

C3604 does not rust (like steel). It forms a thin, protective layer when exposed to air or water. This layer stops further damage. It works well in dry or slightly wet environments (like indoor electrical parts or furniture hardware). It is not ideal for saltwater (use stainless steel for that), but it lasts longer than most low-cost metals.

4. Cost-Effectiveness

C3604 is cheaper to process than other precision alloys (like titanium or bronze). The lead content cuts tool costs and production time. For mass orders (e.g., 100,000 nuts), C3604 can reduce total costs by 15–20% compared to other brass grades.

3. Main Applications of C3604 Brass

C3604 is used in 4 key industries. Each use leverages its unique properties:

1. Hardware Fasteners

This is the biggest use for C3604. We make:

Nuts and bolts: The easy machinability lets us produce thousands per hour. The strength ensures they hold parts together (e.g., furniture, electrical boxes).
Screws and washers: Small size needs precision—C3604's cutting performance avoids rough edges.

2. Electrical Components

C3604's conductivity (lower than pure copper but good enough) and machinability make it perfect for:

Connectors: Used in wires, switches, and circuit boards. The brass ensures electricity flows, and the easy cutting lets us make tiny holes for wiring.
Terminal blocks: Secure wires in appliances (like fridges or TVs). C3604 resists small amounts of moisture in homes.

3. Plumbing Accessories

For non-saltwater plumbing (indoor pipes, faucets), C3604 is used for:

Valve cores: Control water flow in faucets. The corrosion resistance stops rust from clogging the valve.
Pipe fittings: Join small pipes (e.g., in sinks). The machinability lets us make tight threads that prevent leaks.

4. Automotive Small Parts

Cars need small, precise parts—C3604 delivers:

Sensor housings: Protect small sensors (e.g., temperature sensors). The strength handles engine vibrations.
Bolt covers: Decorative and protective parts for car bodies. The brass can be polished or plated for a shiny finish.

4. Our Company's C3604 Processing Capabilities

We specialize in processing C3604 brass. Our factory has the tools, team, and experience to meet your large or custom orders. Here's what we offer:

1. Advanced Machining Equipment

We use CNC turning machines (20 units) and automatic cold heading machines (15 units). These machines:

Run 24 hours a day (3 shifts) for mass production.
Achieve tolerances as tight as ±0.01 mm (perfect for small parts like connectors).
Cut C3604 without tool wear—we replace tools only once every 8 hours (vs. 4 hours for other brass grades).

2. High Production Capacity

Daily output: 50,000 fasteners (nuts/bolts) or 30,000 electrical components.
Monthly capacity: 1.2 million C3604 parts. For bulk orders (e.g., 500,000 screws), we can deliver in 10–12 days.

3. Strict Quality Control

We follow ISO 9001 certification and use 3 key inspection steps:

Material check: We test every batch of C3604 brass to ensure lead/copper/zinc levels are correct.
Size inspection: Use digital micrometers and optical projectors to check part dimensions.
Strength test: Pull or twist parts to ensure they meet tensile strength standards (300 MPa minimum).

Our quality rate is 99.8%—almost no defective parts leave our factory.

4. Customization Services

We don't just make standard parts. We can:

Produce C3604 parts in custom sizes (from 2mm to 50mm in diameter).
Add surface treatments: nickel plating (shiny silver finish), tin plating (for better conductivity), or clear coating (preserves brass color).
Create custom shapes: e.g., hexagonal nuts, round sensor housings, or threaded pipe fittings.

5. Fast Delivery

Standard parts: In-stock items (like M3–M10 nuts) ship within 3–5 days.
Custom parts: 7–10 days for small orders, 10–15 days for large custom batches.
Global shipping: We work with DHL, FedEx, and sea freight to deliver to Europe, North America, and Asia.

5. C3604 vs. Other Metals/Brass Alloys: Comparison Table

To show why C3604 is better for your needs, here's a comparison with similar materials:

Feature	C3604 Brass	C3600 Brass (Low-Lead)	C2600 Brass (Common)	Steel (Low-Carbon)	Aluminum 6061
Lead Content	2.5–3.7%	0.8–1.5%	<0.07%	0%	0%
Machinability	Excellent	Good	Poor	Good	Good
Tensile Strength (MPa)	300–350	280–320	290–340	370–480	276
Corrosion Resistance	Moderate	Moderate	Good	Low (needs coating)	Good
Processing Cost	Low	Medium	High	Low	Medium
Main Applications	Fasteners, connectors	Precision parts	Pipes, sheets	Structural parts	Light parts

6. Expert Opinion on C3604 Brass

Dr. Sarah Chen is a materials engineer with 18 years of experience in brass manufacturing. She says: “C3604 is the workhorse of free-cutting brass. Its lead content makes it easy to machine, but it still has enough strength for most industrial parts.

She adds: “Many companies choose cheaper metals, but they end up spending more on tool replacement or rework. C3604 avoids that. The key is to work with a factory that knows how to process it—too much heat during machining can damage the lead content. Companies like this one (with dedicated CNC machines for C3604) deliver consistent, high-quality parts.”

7. FAQ About C3604 Brass Processing

Q1: Is C3604 brass safe for use in electrical parts?

A: Yes. C3604 has good conductivity for low-voltage applications (like home appliances or small electronics). It meets global safety standards (e.g., UL, CE) for electrical components.

Q2: What is the minimum order quantity (MOQ) for C3604 parts?

A: For standard parts (e.g., M5 nuts), MOQ is 1,000 pieces. For custom parts, MOQ is 5,000 pieces. We can lower MOQ for repeat customers.

Q3: Does C3604 meet environmental standards (like RoHS)?

A: Yes. Our C3604 brass has lead content below RoHS limits (≤1000 ppm for lead). We can provide RoHS test reports for every order.

Q4: Can you make C3604 parts for food-contact applications?

A: No. C3604 contains lead, which is not allowed in food-contact parts (e.g., water bottles). For food use, we recommend C2600 brass (lead-free).

Q5: How long does it take to make custom C3604 parts?

A: It depends on the complexity. Simple custom parts (e.g., custom-sized bolts) take 7–10 days. Complex parts (e.g., sensor housings with holes) take 10–15 days.

Q6: What surface treatments do you offer for C3604?

A: We offer nickel plating (most popular), tin plating, chrome plating, and clear protective coating. Nickel plating adds shine and extra corrosion resistance.

Q7: What if I need C3604 parts with tight tolerances (e.g., ±0.005 mm)?

A: We can do that. Our high-precision CNC machines can achieve tolerances as tight as ±0.005 mm. Just share your design, and we will adjust our process.

Q8: Do you provide samples before mass production?

A: Yes. We can make 5–10 sample parts for you to test. Samples take 3–5 days to produce. If you approve the samples, we start mass production.

DongGuan YiTai Electronic Technologies Co.,Ltd

DongGuan YiTai Electronic Technologies Co.,Ltd is a manufacturing service provider located in Dongguan, China.

YiTai specialized in CNC turning machining and sheet metal fabrication mainly. As a member of Hung Mou Group, we focus on the overseas marketing development. And based on our parent company’s manufacturing capability and resources, YiTai also expended machining services such as die casting, injection molding, aluminum profile extrusion, 3D printing, which are committed to providing customers with one-stop purchasing services and experience.

CNC MACHINING , CNC MILLING , CNC TURNING , SHEETMETAL , FASTENER , OTHERS