Comprehensive analysis of brass turned parts: processing advantages, challenges and application areas

In modern manufacturing, brass turned parts have become indispensable key components in many industrial fields due to their unique material properties and excellent processing performance. From precision electronic connectors to durable plumbing valves, from automotive fuel systems to high-end medical devices, brass turned parts play an important role in industrial production with their excellent conductivity, corrosion resistance and machining performance.

As the manufacturing industry develops towards high precision and high efficiency, the quality requirements for brass turned parts are also getting higher and higher. Understanding the characteristics of brass materials, mastering their processing technology, and recognizing the characteristics of application fields are of great significance to improving product quality and reducing production costs. This article will systematically introduce various aspects of brass turned parts and provide a comprehensive reference for personnel in related industries.

1. What are brass turned parts?

(1) Basic definition and characteristics

Brass turned parts refer to precision mechanical parts made by cutting brass materials using various lathes (including ordinary lathes, CNC lathes, Swiss-type lathes, etc.). Such parts usually have complex geometric shapes and strict dimensional tolerance requirements, and have high surface quality requirements. They are widely used in occasions that require good electrical conductivity, thermal conductivity or corrosion resistance.

Compared with casting or forging processes, turning can achieve higher dimensional accuracy and better surface quality. Modern CNC lathes can achieve a processing accuracy of ±0.005mm, and the surface roughness can reach Ra0.4μm or less, which fully meets the use requirements of most precision parts.

(2) Material composition and classification

Brass is a general term for copper-zinc alloys. According to different alloy components and performance characteristics, it can be divided into the following categories:

1) Ordinary brass (such as C26000):

The copper content is about 70%, and the zinc content is 30%. It has good comprehensive properties and is the most commonly used brass material.

2) Free-cutting brass (such as C36000):

Adding about 3% lead to ordinary brass significantly improves the cutting performance and is particularly suitable for mass production.

3) High-strength brass (such as C46400):

Adding elements such as tin and aluminum to improve strength and corrosion resistance, suitable for occasions with large forces.

4) Special brass:

Adding elements such as silicon and manganese according to special needs to obtain specific physical and chemical properties.

(3) Typical products and applications

There are many types of brass turning parts, mainly including:

●Shaft parts: various specifications of rotating shafts, spindles, etc.

●Connectors: threaded fasteners, pipe joints, etc.

●Electronic components: connector terminals, connectors, etc.

●Valve components: valve cores, valve seats, etc.

●Other precision parts: sleeves, bushings, nozzles, etc.

These products usually require strict dimensional tolerances (up to ±0.01mm) and excellent surface quality (Ra0.8μm or less), and some also require subsequent electroplating or passivation treatment.

2. Turning characteristics of brass

(1) Effect of physical properties on processing

Brass has a series of unique physical properties that directly affect its turning performance:

1) Lower hardness and strength:

The Brinell hardness of brass is usually between HB80-120, which is much lower than that of steel, which makes the cutting force required during cutting smaller and the tool wear lower. Compared with stainless steel, the tool life can be extended by 3-5 times when machining brass.

2) Good ductility:

Brass has a certain plastic deformation ability, which makes it less likely to produce defects such as cracks during processing, but it may also make chip control difficult.

3) Excellent thermal conductivity:

The thermal conductivity of brass is about 120W/m·K, which can quickly conduct cutting heat away to avoid local overheating of the workpiece and tool.

(2) Advantages in machining performance

Based on the above physical properties, brass exhibits excellent machining performance:

1) High cutting speed:

Brass allows a cutting speed of 200-300m/min, which is 2-3 times that of ordinary carbon steel, greatly improving machining efficiency.

2) Good chip breaking performance:

Especially for leaded brass, the chips can break naturally during the cutting process and will not be entangled on the tool or workpiece, reducing machining interruptions.

3) Excellent surface quality:

Under reasonable parameters, the surface roughness below Ra0.8μm can be achieved without polishing, meeting the requirements of most precision parts.

4) Good dimensional stability:

Brass has a relatively low thermal expansion coefficient and small dimensional changes during machining, which is conducive to ensuring machining accuracy.

(3) Machining differences of brass with different compositions

Although brass has excellent turning performance overall, brass with different compositions have certain differences in machining characteristics:

1) High zinc brass (zinc content exceeds 40%):

Tool sticking may occur, requiring the use of tools with special coatings or adjustment of cutting parameters.

2) Leaded brass:

The best cutting performance, but attention should be paid to lead dust protection.

3) Lead-free brass:

Good environmental performance, but the cutting performance is slightly inferior to leaded brass.

4) High-strength brass:

The cutting force is large and the tool wears relatively quickly.

Understanding these differences will help to select the appropriate processing technology for different materials.

3. Significant advantages of brass turning

(1) Production efficiency advantage

Brass turning has obvious advantages in production efficiency:

1) High material removal rate:

Because high cutting speed and large cutting depth are allowed, more material can be removed per unit time.

2) Long continuous processing time:

The tool wear is small, and continuous processing can be carried out for a long time without frequent tool changes.

3) Less auxiliary time:

Good chip breaking performance reduces the time for cleaning chips; fast heat dissipation can save complex 4) cooling system.

Actual production data shows that the overall efficiency of producing brass turned parts is usually 30%-50% higher than that of processing stainless steel.

(2) Economic Benefit Analysis

From an economic perspective, brass turning has many advantages:

1) Low tool cost:

The life of carbide tools can reach 5 times that of stainless steel processing, which greatly reduces tool costs.

2) Energy saving:

Lower cutting force means smaller machine power requirements, and long-term use can save a lot of electricity.

3) High material utilization:

The utilization rate of brass bars can usually reach more than 85%.

4) Low quality cost:

Few processing defects, low scrap rate, and stable quality.

Comprehensive calculations show that the processing cost of brass turned parts is usually 40%-60% lower than that of similar stainless steel parts.

(3) Quality advantage

Brass turned parts have many advantages in quality:

1) High dimensional accuracy:

It can stably achieve IT6-IT7 level accuracy.

2) Good surface quality:

The surface roughness after fine turning can reach Ra0.4μm or less.

3) Stable performance:

The internal structure of the material is uniform and the mechanical properties are consistent.

4) Beautiful appearance: 

Brass itself has a beautiful golden luster and does not require additional surface treatment. These quality advantages make brass turned parts particularly suitable for applications with high requirements for precision and appearance.

4. Main challenges faced by brass turning

(1) Technical difficulties in the processing process

Although brass has good cutting performance, some technical challenges are still encountered in actual processing:

1) Tool sticking problem:

 High zinc brass is prone to built-up edge during cutting, affecting processing quality and tool life.

2) Dimension control:

 Soft materials are easy to deform during clamping and cutting, affecting dimensional accuracy.

3) Surface integrity: 

Improper processing parameters may cause surface microscopic defects.

4) Chip control: 

Some brasses may produce long and continuous chips, affecting processing safety.

(2) Limitations brought by material properties

The material properties of brass also bring some processing limitations:

1) Strength limitation: 

It is not suitable for occasions with extremely high stress.

2) Temperature limitation: 

Softening may occur at high temperatures, affecting performance.

3) Environmental issues:

Machining of lead-containing brass requires special protection.

4) Cost factors:

The price of lead-free brass is relatively high.

(3) Solutions and countermeasures

In response to the above challenges, the following measures can be taken:

1) Optimize tool selection:

Use tools with sharp cutting edges and special coatings.

2) Improve clamping methods:

Use hydraulic clamps, special soft jaws, etc.

3) Adjust process parameters:

Reasonably set cutting speed, feed rate, etc.

4) Improve auxiliary systems:

Equip with chip removal, dust removal and other devices.

5) Strengthen process monitoring:

Implement online testing and quality control.

5. Core application areas of brass turned parts

(1) Application in the electrical and electronic industry

In the electrical and electronic field, brass turned parts are mainly used for:

●Connector components: including pins, sockets, etc., requiring high conductivity and dimensional accuracy.

●Relay parts: contacts, conductive sheets, etc., requiring good elasticity and wear resistance.

●Switch elements: contact parts of various switches.

●Electromagnetic shielding parts: utilize the electromagnetic shielding properties of brass.

These applications usually require the material conductivity to be ≥28%IACS and the surface roughness to be less than Ra0.8μm.

(2) Applications in plumbing and sanitary ware

Plumbing and sanitary ware are traditional applications for brass turning parts:

●Valve parts: valve core, valve stem, valve seat, etc.

●Pipe connections: pipe joints of various specifications, tees, etc.

●Faucet components: key components such as main body and valve core.

●Metering instruments: precision parts in water meters and gas meters.

This type of product requires good corrosion resistance and usually uses lead-free brass materials.

(3) Applications in the automotive industry

In automobile manufacturing, brass turning parts are mainly used in:

●Fuel system: nozzles, oil pipe joints, etc.

●Braking system: brake cylinder parts.

●Sensor components: housings and connectors of various sensors.

●Other functional parts: such as door lock parts, wiper components, etc.

Automotive brass parts usually require special properties such as oil resistance and high temperature resistance.

(4) Mechanical equipment manufacturing

Brass turning parts are widely used in the field of mechanical equipment manufacturing, mainly covering the following aspects:

● Transmission parts: gears, worm gears, transmission shafts, etc., requiring high precision (IT6-IT7 grade) and wear resistance (hardness ≥ HB150).

● Bearings and bushings: sliding bearing rings, bushings, etc., using the self-lubricating and anti-seizure ability of brass.

● Fastening and connecting parts: nuts, bolts, flanges, etc., often using high-strength brass (such as H62, H65).

● Hydraulic and pneumatic components: pump bodies, valve cores, joints, etc., need to meet high-pressure sealing requirements.

● Precision mold accessories: guide pins, locating pins, etc. of injection molding machines and stamping machines, with a surface roughness of usually ≤Ra1.6μm.

This type of application has high requirements on the mechanical strength and processing accuracy of the material, and some parts need to be nickel-plated or phosphated to enhance wear resistance.

6. Summary

Brass turned parts occupy an important position in modern manufacturing due to their unique performance advantages. In the future, brass turning will achieve a higher quality and lower cost production model, providing better precision parts solutions for various industries. For manufacturers or people in related industries, in-depth understanding of brass material properties and continuous optimization of processing technology will be the key to improving competitiveness.