Types of Metals for CNC Machining Materials
(Properties, post-processings, and application explained)

Updated: Jan. 11, 2024

CNC metals are widely used for prototype parts to engineering models to produce components. CNC-machined metals can be widely used in industries from automotive to aerospace. Some metals are generally used, which are highly machinable and suitable for design testing at a relatively low cost, for example, aluminum.

 

Other metal CNC machining materials, like titanium, can withstand extremely harsh environments and is very durable. Titanium can endure the temperature up to 1600℃. Considering the typical metal properties of high heat deflection, high impact resistance, and high corrosion, machined metal alloys can be the best materials for your custom parts.

 

In this article, we will introduce the top 12 metals for CNC machining for your on-demand custom manufacturing. You can learn each metal’s properties, types, and surface finishes.

1. Aluminum for CNC machining

With an excellent strength-to-weight ratio, Aluminum is considered to be a lightweight metal. For parts with metallic level strength required, aluminum is an ideal choice. But for mass application, the weight is still a concern. Aluminum density is approximately 2.70 g/cm³.

Main Properties:

Light, durable and functional

Corrosion-resistant

Ductile

Non-Ferrous/Non-Magnetic

Post-processing:

There are many post-processing choices for aluminum CNC machining parts, which include sandblasting, anodizing, brushing, polishing, Alodine, and powder coating. Among them, sandblasting and anodizing are often used together to create a consistent, textured aesthetic finish, and enhance corrosion resistance with color choices.

Application:

Due to its excellent strength-to-weight ratio, good machinability, and general versatility, Aluminum is widely used in the medical, automotive, and aerospace industries. Aluminum is ideal for functional prototypes, production components, tooling, etc.

Grades:

There are many different alloys for aluminum. The below table shows 12 aluminum grades in CNC machining.

GradePropertiesApplications
Aluminum 6061-T6 | 3.3211 | 65028 | AlMg1SiCuA precipitation-hardened aluminium alloy composed mostly of magnesium and silicon.
High strength 
Good weldability 
Corrosion resistant
Can be extruded
Automotive, aircraft, electronics, ship buildings, hardware, sporting products,  scaffolds, rail coaches, and machine parts etc.
Aluminum 7075-T6 | 3.4365 | 76528 | AlZn5,5MgCuAn alloy of aluminium that has been strengthened with zinc and magnesium.
High strength
Tough
Resistant to fatigue
Excellent machinability
Different automotive parts include meter shafts, gears, regulating valves, interiors, aircraft structure parts, defense, and many more.
Aluminum 5052 | EN AW-5052 | 3.3523 | AlMg2,5A high magnesium alloys and like all 5000-series has a fairly high strength.
Can be hardened to a significant degree by cold working.
Good corrosion resistance
Hydraulic tubes,kitchen appliances,cabinets
small boats,home freezers, aircraft tubes,
fencing.
Aluminum 6060 | 3.3206 | AlMgSi Architectural sections, frames,lightings,railling
ladders,furniture,fences,flooring
Aluminum 6082 | 3.2315 | 64430| AlSi1MgMnExcellent corrosion resistance
High strength – the highest of the 6000 series alloys.
Difficult to produce thin walls.
General purpose high duty applications,structural frames,pylons,towers,bridges
Aluminum 5083-H111 | 3.3547 | 54300| AlMg4.5Mn0.7High resistivity to salty water, chemicals, attacks.
High strength and good corrosion resistance.
Excellent weldability.
Marine industry
Railroad cars
Vehicle bodies
Pressure vessels
Aluminum 6063 | EN AW-6063 | 62400| AlMg0,7SiA medium strength alloy commonly referred to as an architectural alloy.
Very good corrosion resistance and is suitable for decorative anodising.
Known as an extrusion alloy.
Architectural products
Door and windows frames
Pipe and tubes for irrigation systems
Electrical components
Aluminum 2024-T351 | 3.1355 | 24530 | AlCu4Mg1Good fatigue resistance and strength
Excellent toughness at moderate to high strength levels and improved fracture toughness.
Available in T3, T4 and T8 tempers and in the annealed state.
Aircraft fuselage
Commercial & military aircraft
Wing tension members
Critical Aircraft structures
Aluminum 7050 | EN AW-7050 | 3.4144| AlZn6CuMgZrCommercial aerospace alloy.
Heat treatable
High toughness
Strong mechanical strength
Good stress corrosion cracking resistance.
Fuselage frames
Bulkheads
Wing skins
Aerospace structures
Commercial & military aircraft applications
Aluminum MIC6A cast aluminum plate
Excellent accuracy and machinability.
Produced by casting which results in stress relieving properties.
Light weight, smooth and free from tension, contaminants and porosity.
Machining Components
Aerospace & automotive components
Electronics
Laser technology
Aluminum 2017A | 3.1325 | 24530 | AlCu4MgSiA heat-treatable alloy with fair workability and formability.
Welding is possible for this alloy, but it reduces its corrosion resistance, therefore heat treatment is required afterwards to restore it.
Screw machine products and fittings
Pulleys and gauges
Rivets
General structural components
Fasteners
Aircraft components
Aluminum 2014 | 3.1255 | 24345 | AlCu4SiMgA high strength alloy which is widly used in the aerospace industry.
Good machinability in certain tempers.
Commonly extruded in bars and profiles.
Aerospace & Defense industry
Truck frames
7075 cnc machined part

2. Stainless steel for CNC machining

Stainless steel has outstanding properties of high strength, heat resistance, and exceptional corrosion resistance. Especially due to its corrosion resistance, stainless steel finds many applications from the medical to the power generation industry. It is a crucial metal to many industries.

 

Main Properties:

Good corrosion resistance

Excellent ductility

Can be forged, machined, spark-eroded, or welded.

 

Post-processing:

Typical post-processing for stainless steel cnc parts includes brush, mechanical polish, electropolishing, Passivation, sandblasting, and powder coating. Passivation is the most frequently used surface treatment process for stainless to enhance its corrosion resistance by removing free iron on the surface. After Passivation treatment, stainless steel has a clean, bright surface.

 

Application:

Stainless steel CNC-machined parts are widely used in industries from culinary, automotive, medical, aerospace, and industrial parts. Whether it is functional prototypes, customized parts, spare parts, or production parts, stainless steel is all suitable.

 

Grades:

Based on its crystalline structure, stainless steel is classified into 4 types, Austenitic, ferritic, martensitic, and duplex. In our blog about Stainless Steel CNC Machining, you can learn more about the classification. Below are the 10 grade common stainless steel grades in CNC machining.

 

GradeClassificationPropertiesApplications
Stainless steel 304/304L | 1.4301/1.4307 | X5CrNi18-10/X2CrNi18-9AusteniticNon-magnetic steel and it is less electrically and thermally conductive than carbon steel.
Machinable and weldable.
Also know as A2 stainless steel, 18/8 stainless steel, UNS S30400, 1.4301.
304L stainless steel is the low carbon version of stainless steel 304.
Food handling and precessing equipment
Food processing
Architectural panelling
Sanitary ware and troughs
Tubing
Stainless steel 316/316L | 1.4401/1.4404 | X5CrNiMo17-12-2/X2CrNiMo17-12-2AusteniticSuperior corrosion resistance particularly in chloride containing environments.
Good elevated temperature strength.
The low carbon version 316L has even better corrosion resistance in welded structures.
Chemical and petrochemical industry
Food processing
Pharmaceutical equipment
Medical devices
Potable water
Wastewater treatment
Marine applications
Stainless steel 303 | 1.4305 | X8CrNiS18-9AusteniticReadily machineable than 304.
Lower corrosion resistance and toughness than 304.
Aircraft applications including fittings
Shafts and spindles
Automatic screw machine applications
Medical devices with screw threads
Drilled or tapped holes
Pump and valve parts
Architectural applications
Nuts and bolts
Stainless steel 301 | 1.4310 | X10CrNi18-8AusteniticBright attractive surface
Resistance to atmosphere corrosion.
Well suited for welding, forming and drawing.
Rail car structural components
Air frame sections
Automotive wheel covers
Wiper blade clips and holders
Stainless steel 416 | 1.4005 | X12CrS13MartensiticHighest machinability of all stainless steels.
Limited corrosion resistance, formability and weldability are limited.
Available in highly tempered, hardened or unhardened forms.
Valves
Pump & motor shafts
Washing machine components
Gears & bolts
Nuts & studs
Automatic screw-machined components
Stainless steel 420 | 1.4028 | X30Cr13MartensiticGood corrosion resistance, strength and hardness.
Can also be hardened through heat treatment.
It is magnetic in the annealed and hardened version.
Shear blades
Needle valves
Surgical equipment
Stainless steel 440C | 1.4125 | X105CrMo17MartensiticHigh strength, moderate corrosion resistance and good hardness and wear resistance.
Well suited for ball bearing and valve parts.
Gage blocks
Ball bearings and races
Molds and dies
Valve components
Measuring instruments
Stainless steel 17-4 PH | 1.4542 | X5CrNiCuNb16-4 – Annealed stateDuplexHigh strength, good corrosion resistance and toughness in both base metals and welds.
Also known as 17-4 PH, UNS S17400, and Grade 630.
Aerospace applications
Base plates
Chemical processing equipment
Oil and petroleum refining equipment
Nuclear components
Stainless steel 15-5 | 1.4545 | X5CrNiCu15-5 – Annealed stateDuplexGood toughness and even better corrosion resistance compared to 17-4 stainless steel.High pressure corrosive environments Gears & Fasteners
Fittings & shafts in aircraft components
Chemical process equipment
Equipment for nuclear reactors
Stainless steel 2205 Duplex | 1.4462 | 2205 | X2CrNiMoN 22-5-3DuplexExcellent corrosion resistance, particularly stress corrosion cracking, corrosion fatigue and erosion and ensures high strength.Environments containing chlorides and hydrogen sulphide
Flue gas filters
Chemical tanks
Heat exchangers
Acetic acid distillation components
Stainless steel 430 | 1.4016 | X6Cr17FerriticGood corrosion resistance, formability, ductility and magnetic.
Resistance to nitric attack and is a very popular choice for domestic appliances and decorative trim.
Low cost sinks
Refrigerators
Stove element supports
Scientific apparatus
Fasteners
Flue linings
stainless steel cnc machining

3. Carbon steel for CNC machining

Carbon steel is an alloy mainly composed of iron and carbon, with typical carbon content from 0.08% to 2.11%. Due to different carbon content, it is classified into low carbon steel, also named mild steel, medium carbon steel and high carbon steel.

 

Main Properties:

Versatile types.

Cost-effective.

Excellent machinability.

Good weldability.

 

Post-processing:

Powder coating, bluing, spray painting, galvanization, and plating are the common post-processing treatments for carbon steel CNC machined parts.

 

Application:

CNC-machined carbon steel finds widespread applications across wide industries, including automotive, aerospace, construction, oil and gas equipment, tool and die-making consumer goods, and medical devices.

 

Grades:

Below are the most used carbon steel grades in CNC machining.

GradePropertiesApplications
Mild steel 1018 | 1.1147 | C18 |16MnGood balance of ductility, strength and toughness.
Excellent weldability.
Best steel for carburizing parts.
Industrial applications requiring more wear-resistance and strength
Gears & Pins
Rams & Shafts
Rolls & Sockets
Axles
Medium carbon steel 1045 | 1.0503 | C45 | EN8Good strength and impact properties. Reasonably good weldability in the hot rolled or normalised condition.
Low hardening capabilities.
Axles
Bolts
Forged connection rods
Crankshafts
Torsion bars
Mild steel A36 | 1.025 | Fe 410Strong, tough, ductile, formable and weldable.Structural application
Automotive industry
Heavy equipment
Oil & Gas industry
carbon steel cnc machining part with zinc plating

4. Alloy steel for CNC machining

Compared to mild steel, alloy steel is one type of steel that contains other elements besides iron and carbon. The other elements can be chromium, nickel, manganese, molybdenum, and vanadium, which are known as strengthening elements to significantly improve mechanical properties.

 

Main Properties:

Excellent mechanical properties.

High accuracy.

High repeatability.

Tough with high fatigue strength, and abrasion resistant.

Ductile.

 

Post-processing:

Plating, powder coating, nitriding, and heat treatment are the post-treatments that are often used to improve alloy steel CNC machined parts’ properties.

 

Application:

Due to their strength, durability, and versatility, CNC-machined alloy steel parts are widely used in diverse industries from automotive, aerospace, construction and medical devices.

 

Grades:

Below are the most used alloy steel grades in CNC machining.

GradePropertiesApplications
Alloy steel 4140 | 1.7225 | EN19 | 42CrMo4Low alloy steel with chromium and molybdenum content ensuring reasonable strength.
Good atmospheric corrosion resistance.
Heavy duty shafts
Connecting rods
High tensile bolts
Alloy steel 4340 | 1.6511 | 36CrNiMo4 | EN24Better toughness and strength than 4140.
Medium carbon low alloy steel.
Can be heat treated to high strength levels while maintaining good toughness, wear resistance and fatigue strength levels, combined with good atmospheric corrosion resistance, and strength.
High tensile applications
General engineering parts
Connecting rods & bolts
alloy steel 4140 cnc machining

5. Tool steel for CNC machining

Tool steel is one type high high-carbon alloy steel, specially designed for tools, dies, and cutting implements. Due to its high hardness, wear resistance, and toughness, tool steel is suitable for frequent and heavy-duty use. The elements such as chromium, vanadium, tungsten and molybdenum inside the tool steel enhance its properties.

 

Main Properties:

Excellent high-hardness

High stiffness.

Abrasion resistant.

Strong.

 

Post-processing:

There are 3 post-treatments for alloy steel CNC machined parts, coating, nitriding, and heat treatment. A coating like TiN, TiCN, DLC is to improve wear resistance and reduce friction. Nitriding can improve hardness, wear resistance, and corrosion resistance. Heat treatment is to increase hardness and toughness.

 

Based on our manufacturing experience, almost all the tool steel parts need to be heat treated. The different heat treatment processes will yield different hardness. The higher the hardness is, the more brittle the part will be. To achieve the desired balance of hardness, toughness, and wear resistance, we need to select the right heat treatment process carefully.

.

Application:

Due to durability, precision, and wear resistance, CNC machined tool steel parts are suitable for cutting tools, molds, dies, and woodworking tools.

 

Grades:

Below are the most used tool steel grades in CNC machining.

GradePropertiesApplications
Tool steel D2 | 1.2379 | X153CrMoV12-1 – Annealed stateExcellent abrasion resistance qualities.
High hardness and mild corrosion resistance in the hardened state.
Good machinability in the annealed state.
Hot forging tools and dies
Hot extrusion tools and dies
Cold forming dies
Tool steel A2 | 1.2363 | X100CrMoV5-1- Annealed stateHigh toughness and dimensional accuracy in hardened state.
Better machinability than D2.
Worse wear and abrasion resistance than D2.
Cutting & Shearing tools
Cold-forming dies
Die casting and molding dies
Tool steel A3 – Annealed stateHigh quality cold work steel that can be oil quanched and tempered. After annealing it can reach hardness of 250HB.
Equivalent grades are: ASTM A681, FED QQ-T-570, UNS T30103.
Cold forging & heading dies
Cold forging dies
Shear blades
Knurling tools
Tool steel O1 | 1.2510 | 100MnCrW4 – Annealed stateGood hardening results and small dimensional changes.Cutting tools
Cold-forming dies
Shearing tools
Die casting and molding dies
Tool steel S7 | 1.2355 | 50CrMoV13-15 – Annealed stateExcellent toughness, high strength and medium wear resistance.
Can be used for both cold and hot working applications.
Cutting tools
Hot forging & extrusion tools
Cold-forming dies
Shearing tools
Tool steel H13 | 1.2344 | X40CrMoV5-1 – Annealed stateGood machinability, good weldability and ductility.
Excellent combination of shock and abrasion resistance, and possesses good red hardness.
Extrusion & pressure dies
Forging & stamping dies
Hot shear blades
tool steel cnc machining

6. Copper for CNC machining

With the symbol CU and atomic number 29, copper is a ductile metal with excellent electrical conductivity, thermal conductivity, and corrosion resistance. 

 

Due to chemical properties, copper can be classified into pure copper, and copper alloy. Pure copper refers to copper with a purity close to or reaching 100%. Copper alloys are with different alloying elements, such as brass (with zinc), bronze (with tin), red copper, etc.

 

When talking with CNC machined copper, we refer to commercially available copper with typically more than 99% pure. The remaining 1% is usually impurities such as oxygen, lead, or silver.

 

Main Properties:

Excellent conductivity

High thermal conductivity

Ductility and malleability

Corrosion resistance

Aesthetic appeal

 

Post-processing:

.Polishing, brushing, electropolishing, electroplating and passivation are usually used for CNC machined copper. The CNC machining copper components are prone to oxidation and become dark soon. Passivation treatment is always applied to improve its resistance to oxidation in ECOREPRAP.

 

To keep copper’s thermal and electrical conductivity while improving corrosion resistance, electropolishing is always used to achieve an extremely smooth and shiny surface.

 

Electroplating is also frequently used to avoid oxidation and maintain thermal and electrical conductivity at the same time. Especially, gold plating and silver plating can get low contact resistance while keeping excellent conductivity and solderability.

 

Application:

Due to copper’s properties, it is widely used in art and sculptures, electrical conductors, heat exchangers, plumbing fittings, and musical instruments.

 

Grades:

Below are the most used copper grades in CNC machining.

GradePropertiesApplications
Copper C101 | CU OFEHigh thermal conductivity. 
High percentage of Copper in it – 99.99%.
Electronics
Automotive
Domestic Appliances
Cold formed components
Copper C110 | CU ETPHigh malleability, ductility, excellent heat and electrical conductivity.
Easy to form thin protective patina that is relatively impermeable.
Circuit breakers
Electrical instruments
Vacuum capacitors
Magnetrons
Purple Copper T2Oxygen-free copper.
High electrical conductivity.
Excellent thermal conductivity.
Malleable and ductile.
Corrosion-resistant to some extent.
Electrical wiring and components.
Conductive elements in electronics.
Construction and architecture.
Oxygen-Free Copper – TU2:High electrical conductivity due to low oxygen content.
Excellent corrosion resistance.
Malleable and ductile.
Good thermal conductivity.
Electrical conductors and connectors.
Superconductor applications.
Components in the aerospace industry.
High-performance audio equipment.
Beryllium  Copper C17200High strength and hardness.
Excellent conductivity, comparable to pure copper.
Good corrosion resistance.
Non-magnetic.
Springs and contacts in electronics.
Tools requiring high strength and conductivity.
Bearings and bushings.
Aerospace components.
copper cnc machining part

7. Brass for CNC machining

Brass is a copper-zinc alloy, which contains zinc and other elements, for example, lead, aluminum, and iron. Due to the copper’s existence, brass has good electrical and thermal properties. It also has good wear resistance and machinability. Among all copper alloys, brass is the most machinable type.

 

Compared with copper, brass is mechanically stronger, has lower friction, and better corrosion and wear resistance. This makes brass a versatile copper alloy. The outstanding properties of brass make CNC machining brass find wide mechanical applications in industry require corrosion resistance, for example, marine industry.

 

Main Properties:

Nice malleability and ductility

Corrosion resistance

Thermal conductivity

Electrical conductivity

 

Post-processing:

For cnc machining brass components, passivation is always applied to improve the corrosion resistance.

 

Application:

CNC-machined brass parts can be used for industrial valves, fitting, connectors, radiators, decorative arts, musical instruments, plumbing, electronics, and automotive parts.

 

Grades:

Below are the most used brass grades in CNC machining.

GradePropertiesApplications
Brass C360 | 2.0375 | CuZn36Pb3 | 319 grade 2Known as free-cutting brass or free machining brass.
Highly machinable due to the relatively high amount of lead.
Gears, screw machine parts, and valve components.
Brass C260Know as Cartridge Brass.Ammunition cartridges.
Rivets, hinges, and radiator cores.
Brass Cz121 | C38500 | 2.0401 | CuZn39Pb3Most suited copper alloy for machining.
Has a lubricant and a chip breaker behavior. Great strength and excellent corrosion resistance.
Locks
Hinges
High speed machined components
brass cnc machining part

8. Bronze for CNC machining

Brass is copper alloy containing copper and tin(about 35%) and lead(up to 8%). Due to the soft element lead existence, bronze is easily machinable. Because bronze has good corrosion resistance, it is always used as bearings as well as marine pumps and marine fittings where corrosion resistance against seawater is a must.

 

The mechanical properties of bronze are not very good compared to other machinable metals such as aluminum. The low friction property of bronze makes it ideal for parts that undergo contentious frictional contact.

 

Bronze, brass, and other copper alloy all have good electrical, machinable, and corrosion-resistant properties.

 

Main Properties:

Good malleability and ductility

Good conductivity

Better strength

General corrosion resistance

 

Post-processing:

Bronze is likely to form an oxidation layer on the surface. The coating is not a must because it does not corrode like other metals. Sandblasting, as machined surface and chemical coatings, are also common for bronze CNC milled parts to prevent oxidation.

 

Application:

Bronze is suitable for bearings.

 

Grades:

Below are the most used bronze grades in CNC machining.

GradePropertiesApplications
Bronze 932Known as bearing bronze.
Excellent anti-friction properties.
Bearings, bushings, wear strips, and other light-duty applications.
Tin Bronze – QSn-6-6-3Good resistance to corrosion
Moderate to high strength
Reasonably good machinability
Good resistance to wear and abrasion
Bearings and bushings
Marine components
Gears and connectors
Musical instruments
Artistic and decorative castings

9. Titanium for CNC Machining

Titanium is a lightweight metal with an excellent strength-to-weight ratio, good corrosion even at extreme temperatures, and low thermal expansion.

 

Titanium is available in pure and alloyed form. Pure Titanium also has other elements inside, less than 1%, namely iron and oxygen. Titanium alloy can have significantly improved strength.

 

As an advanced material with sterilization biocompatibility, and corrosion resistance, Titanium is an ideal choice for many engineering challenges by the medical, energy, chemical processing, and aerospace industries.

 

Main Properties:

High strength-to-weight ratio

Excellent corrosion resistance 

Biocompatible

High-temperature resistance

Low thermal expansion

Enhanced durability

 

Post-processing:

Sandblasting, anodizing, passivation, and vibratory tumbling are common post-processing treatment for Titanium cnc machining parts

 

Application:

Due to its outstanding properties, Titanium is widely used to make aerospace components like aircraft frames, landing gear, engine components, medical implants, automotive components like exhaust systems, valves, and suspension parts, and sports equipment like bicycle frames, golf clubs, and tennis rackets, marine parts like boat components, propellers, and underwater exploration equipment, military, and defense parts, UAV or done parts like UAV frames, structural elements, fasteners, and other critical parts.

 

Grades:

Below are the most used Titanium grades in CNC machining.

GradePropertiesApplications
Titanium Grade 1 | 3.7025Commercially pure Titanium
Excellent corrosion resistance and strength-to-density ratio.
Low thermal expansion coefficient and lower thermal stresses.
Outstanding biocompatibility.
Airframe components
Cryogenic vessels
Heat exchangers
CPI equipment
Condenser tubing
Pickling baskets
Titanium Grade 2 | 3.7035Commercially Pure Titanium with some oxygen content
Unalloyed or “commercially pure” Titanium.
A relatively low level of impurity elements and yield strength that places it between grade 1 and 3.
Light-weight, highly corrosion resistant.
Excellent weldability.
Aerospace
Marine industry
Medical industry
Titanium Grade 5 | 3.7164 | Ti6Al4VAlloyed with aluminum and vanadium
Stronger than Grade 2, equally corrosion-resistant, and has an excellent bio-compatibility.
Aerospace
CNC machining Titanium

10. Magnesium Alloy for CNC Machining

Though usually used as a die-casting material, Magnesium is becoming more popular for CNC machining because of its high strength-to-weight ratio. Magnesium is highly machinable and can produce excellent surface finishes because the chips during production are short.

 

However, Magnesium is prone to ignite at high temperatures. During Magnesium CNC milling, a special coolant shall be used. Once on fire, it should be put out with sand. Fire safety considerations are crucial to Magnesium CNC machining.

 

Main Properties:

Lightweight

High strength and stiffness

Superior strength-to-weight ratio

Excellent thermal conductivity

Biocompatibility

 

Post-processing:

For CNC-machined magnesium components, yellowish conductive passivation treatment is always conducted to improve the corrosion resistance and keep electrical conductivity. To improve the surface texture, sandblasting is preferred.  If the CNC machining magnesium parts need to do salt spray testing, spray painting, powder coating, and nickel plating are better choices.

 

Application:

Magnesium’s lightweight nature makes it suitable for aerospace components, and automotive parts, like transmission cases, steering wheels, structural components, electronic devices, and medical implants.

 

Grades:

Below are the most used Magnesium grades in CNC machining.

GradePropertiesApplications
Magnesium AZ31BA magnesium alloy with aluminum (Al) and zinc (Zn) as the primary alloying elements. The numerical designation “31” indicates 3% aluminum and 1% zinc by weight.
Good strength-to-weight ratio.
Moderate corrosion resistance.
Excellent machinability.
Good thermal conductivity
Aerospace components
Automotive parts
Electronics
Medical devices
Sporting goods
Tooling and jigs

11. Nickel Alloy for CNC Machining

Nickel alloy contains nickel and a few other elements. Nickel alloys are known for their excellent corrosion resistance, low coefficient of thermal expansion, and high-temperature strength.

 

Main Properties:

Excellent corrosion resistance 

High-temperature strength

Low coefficient of thermal expansion

 

Post-processing:

Medium tumbling and powder coating are post-processing treatments for CNC machining nickel alloy parts.

 

Application:

CNC-machined nickel alloy parts are extensively used in various industries, including aerospace, chemical processing, electronics, and marine applications. 

 

Grades:

Below are the most used nickel alloy grades in CNC machining.

GradePropertiesApplications
Inconel 718Austenitic nickel-base superalloy
High strength
Outstanding weldability
Resistance to post-weld cracking
Excellent creep-rupture strength
Initially developed for the aerospace industry and is still used for most of the aircraft engine components.
Jet engines
Rocket motors
Spacecraft
Space shuttles
Nuclear reactors
Pumps & turbo pumps
Tooling
Invar 36Nickel-iron alloy
Very low thermal expansion coefficient
Strong, tough, ductile
Magnetic in the temperature range in which exhibits the low expansion characteristics.
Aircraft control
Optical & laser systems
Electronic devices
KovarExpand at a similar rate to glass when exposed to heat.
Low coefficient of thermal expansion.
Excellent dimensional stability at a wide range of temperatures.
Frames for semiconductors
Relay frames and housings
Hermetic seals in aerospace and satellite applications
Implantable medical electronics
Glass encapsulation

12. Zinc Alloy for CNC Machining

Zinc alloy metal is nonmagnetic. It contains zinc as well as other elements like aluminum, magnesium, and copper. 

 

Zamak is a specific family of zinc alloys with a well-defined composition, primarily used in die-casting applications. Zamak is originated as an acronym for the element names in German:.Zink, Aluminium, Magnesium, and Kupfer.

 

Main Properties:

Material with a quite cheap price

Non-magnetic

Good mechanical strength 

Easily machined 

Resist mechanical shocks well

Excellent damping capacity 

Highly ductile

Long-term dimensional stability

 

Post-processing:

Chrome plating, chromate conversion coating(also known as Alodine), and painting are the main post-treatment for Zinc alloy CNC machined parts.

 

Application:

Zinc alloy CNC machined parts find applications in automotive parts like door handles, brackets, and interior trim,  electronics and electrical devices like connectors, housings, and brackets, consumer goods like knobs, and decorative elements in household appliances.

 

Grades:

Below are the most used Zinc alloy grades in CNC machining.

GradePropertiesApplications
Zamak 3Contains 4% aluminum while less than 1% is composed of copper and magnesium.
Good machinability.
Less abrasive to tooling. 
Automotive part shells
Small electric motor casings

13. Metal for CNC Machining Considerations

In this article, we introduce 12 common types of metals materials for CNC machining, aluminum, carbon steel, alloy steel, tool steel, stainless steel, copper, brass, bronze, titanium, zinc, nickel, magnesium, including their properties, post surface finishes and main application explained. Then there comes an important question? How to select the right metal for your CNC machining? What factors needed to be taken into consideration? Read our blog “CNC Machining Materials: Choose the Right One ” and learn more!

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