CNC Machining Materials Types, Characteristics & Applications | How to Select the Right Materials for CNC Machined Components

2019/11/26 16:10:35

There is a diversity of materials that can be processed to produce CNC machined components, featuring almost all of metals and plastics, while different materials have different mechanical properties and cost, which determines the usage and function. How to select the right materials for CNC processing? Follow us to learn about the common CNC machining materials types, characteristics, features, cost, and applications, to help you find the best CNC material option.

CNC machined components

Common CNC Machining Materials Types, Characteristics & Applications

CNC machining working with a wide range of metals, plastics, rubbers, wood, foams, and other materials, what are the features and characteristics of the available ones? What industries or components use these raw materials?

1. Aluminum

One of the most widely applied metals for CNC milling, strong but lightweight, easy to machine and economical, good corrosion resistance.

Aluminum 6061

Characteristics: contains magnesium and silicon, high machinability and low cost, good weldability

Applications: aircraft fittings, automotive parts, bicycle frames, food containers, electronic hardware, couplings, marine parts, etc.

Aluminum 7075

Characteristics: higher strength than 6061, more expensive than aluminum 6061

Applications: aerospace, marine, missile and automotive components, sports equipment, shafts, gears, keys, fuse parts, valve parts, etc. 

2. Brass

Easy to process, cost-effective, has low friction coefficient and high corrosion resistant properties, relatively lower strength.

Brass 260

Characteristics: resistant to most chemicals

Applications: electronic hardware and contacts, aerospace fittings, etc.

Brass C36000

Characteristics: medium strength and medium hardness, high machinability

Applications: nozzles, valve parts, mechanical and architecture parts, etc. 

3. Stainless Steel

A commonly used alloy can be heat treated, corrosion-resistant, high/low temperature resistant, abrasion resistant, chemical resistant, not easy to rust.

Stainless steel 303

Characteristics: high strength, high hardness, higher machinability than 304, 316, 17-4,  and 2205 Duplex

Applications: nuts, bolts, gears, bushings, aircraft components, etc. 

Stainless steel 304

Characteristics: low carbon, good weldability, and formability, high strength, medium hardness, one of the cheapest stainless steel

Applications: screws, household items, food processing, and machinery parts, etc.

Stainless steel 316

Characteristics: higher chemical, crack and corrosion resistance than 304, high strength, medium hardness

Applications: medical implants and surgical instruments, chemical containers, food preparation equipment, marine and architecture areas, etc.

Stainless steel 2205 Duplex

Characteristics: high strength, high hardness, relatively low processability, and high cost.

Applications: marine parts, oil and gas industry, chemical processing, etc. 

Stainless steel 17-4

Characteristics: higher magnetism than 304 and 316, oxidation resistant, extremely high hardness and high strength, more expensive than other types of stainless steel

Applications: turbine blades, chemical vessels, nuclear, marine, medical, aviation and other industries need high hardness and corrosion resistance 

Stainless steel 410

Characteristics: martensitic stainless steel, extremely strong and tough due to high carbon content, can be heat-treated

Applications: valves and nozzles, dental and surgical instruments, pipelines, auto parts, etc. 

Stainless steel 416

Characteristics: the highest machinability of any stainless steel, lower corrosion resistant than 300 series, can be heat-treated, low cost

Applications: valves, gears, studs, nuts, bolts, electrical motors, pumps, washing machine components, and industries require less corrosion resistance, more hardness

Stainless steel 440C

Characteristics: highest carbon content among 400 stainless steel series, can be heat treated and oil quenched

Applications: ball and roller bearings, knife blades, etc. 

4. Copper

Corrosion resistance, thermal conductivity properties and electric conductivity, easy for shaping

Copper C101

Characteristics: oxygen-free, weak against acids, halogens sulfides, and ammonia solutions, high corrosion resistance in most environments, excellent for soldering.

Applications: electrical connectors, transformers, motor components, building fascias, heat sink, cable strips, general engineering, automotive, domestic industries

5. Steel

Steel alloy available for CNC milling, CNC turning with excellent machinability, enhanced formability and specific properties

Steel 1018

Characteristics: low carbon content, easy for welding, case hardening only

Applications: rivets, shafts, spindles, pins, rods, sprocket assemblies, etc.

Steel 1137

Characteristics: high carbon content, hardening directly

Applications: gears, shafts, studs, bolts, nuts, etc.

6. Plastics

With the special properties and lightweight characteristics, some plastics can replace metal in many applications, PVC, PI, PP, POM, PEEK, PLA, Nylon, etc., click here to check out the advantages of POM and how to choose best plastic materials for CNC machining. Dajin Precision as a top CNC machined components manufacturer, providing a large collection of quality metal and plastic CNC machining materials for aerospace, automotive, military, medical, electronics, mechanical and more industries equipment. 

How to Select the Right Materials for CNC Machined Components

The fastest way to determine the optimum CNC machined components materials is to figure out what's your requirements and the characteristics of materials. The factors you should consider are basically included as below.

1. Machinability - The machinability should the priority of the machining materials selection, the one with extremely low processability is not suitable obviously. Some materials like stainless steel 416 and POM are both very easy to machine, which are widely used in a number of CNC machining applications, most of metals and plastics can be processed, more options like wood including hardwood, plywood, and softwood can be chosen from, foam is really lightweight and durable, such as carving foam and rigid foam.

2. Application - Where and how will the CNC machined parts be used? For example, whether the component needs insulation or electrical conductivity? Will it be used in an outdoor or indoor environment? If outdoor, you should take moisture into consideration, the material needs to be oxidation resistant. In addition, stress, temperature, impact, and more environmental attributes can't be ignored. Ask some questions, remove some impossible materials firstly according to certain requirements.

3. Dimensional Tolerance - It will influence the selection of materials, cutting methods, types of machine tools and more important things for the machining process, know about the tolerance your part needs.

4. Weight - The weight level of the CNC machined part or items for equipment depending on what you want to do. Heavier materials are more suitable for applications requiring excessive weight-bearing capabilities and resistance to high-stress loads, while lightweight materials like lots of plastics are ideal for automotive, aerospace, bicycles and other industries need to reduce the weight.

5. Cost - your budget and the cost of materials usually limit the selection of machining parts materials. The more expensive materials often have greater performance but not the most cost-effective. Focus on crucial restrictions and necessary elements your component needed, narrow down it to a minimum, then choose the cheapest one from the materials meet the majority or all of your needs.

Other than these factors, strength, hardness, weldability, chemical resistance, thermal resistance and more attributes related to the function of CNC machining parts should be considered before the decision of which CNC materials to use. 


DAJIN provides excellent quality turning services, precision turned parts, offering professional machining services at competitive price and on timely delivery. With our extensive machining capabilities, we produce the most challenging precision machining parts covering all Industries especially in mass production in automotive industry.