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.
| Grade | Properties | Applications |
| Aluminum 6061-T6 | 3.3211 | 65028 | AlMg1SiCu | A 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 | AlZn5,5MgCu | An 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 | AlMg2,5 | A 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| AlSi1MgMn | Excellent 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| AlMg4.5Mn0.7 | High 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| AlMg0,7Si | A 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 | AlCu4Mg1 | Good 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| AlZn6CuMgZr | Commercial 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 MIC6 | A 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 | AlCu4MgSi | A 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 | AlCu4SiMg | A 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 |
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.
| Grade | Classification | Properties | Applications |
| Stainless steel 304/304L | 1.4301/1.4307 | X5CrNi18-10/X2CrNi18-9 | Austenitic | Non-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/X2CrNiMo17-12-2 | Austenitic | Superior 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 | X8CrNiS18-9 | Austenitic | Readily 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 | X10CrNi18-8 | Austenitic | Bright 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 | X12CrS13 | Martensitic | Highest 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 | X30Cr13 | Martensitic | Good 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 | X105CrMo17 | Martensitic | High 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 state | Duplex | High 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 state | Duplex | Good 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 22-5-3 | Duplex | Excellent 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 | X6Cr17 | Ferritic | Good 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 |
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.
| Grade | Properties | Applications |
| Mild steel 1018 | 1.1147 | C18 |16Mn | Good 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 | EN8 | Good 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 410 | Strong, tough, ductile, formable and weldable. | Structural application Automotive industry Heavy equipment Oil & Gas industry |
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.
| Grade | Properties | Applications |
| Alloy steel 4140 | 1.7225 | EN19 | 42CrMo4 | Low 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 | EN24 | Better 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 |
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.
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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.
| Grade | Properties | Applications |
| Tool steel D2 | 1.2379 | X153CrMoV12-1 – Annealed state | Excellent 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 state | High 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 state | High 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 state | Good 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 state | Excellent 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 state | Good 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 |
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.
| Grade | Properties | Applications |
| Copper C101 | CU OFE | High thermal conductivity. High percentage of Copper in it – 99.99%. | Electronics Automotive Domestic Appliances Cold formed components |
| Copper C110 | CU ETP | High 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 T2 | Oxygen-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 C17200 | High 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. |
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.
| Grade | Properties | Applications |
| Brass C360 | 2.0375 | CuZn36Pb3 | 319 grade 2 | Known 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 C260 | Know as Cartridge Brass. | Ammunition cartridges. Rivets, hinges, and radiator cores. |
| Brass Cz121 | C38500 | 2.0401 | CuZn39Pb3 | Most 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 |
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.
| Grade | Properties | Applications |
| Bronze 932 | Known as bearing bronze. Excellent anti-friction properties. | Bearings, bushings, wear strips, and other light-duty applications. |
| Tin Bronze – QSn-6-6-3 | Good 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.
| Grade | Properties | Applications |
| Titanium Grade 1 | 3.7025 | Commercially 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 | 3.7035 | Commercially 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 | Ti6Al4V | Alloyed with aluminum and vanadium Stronger than Grade 2, equally corrosion-resistant, and has an excellent bio-compatibility. | Aerospace |
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.
| Grade | Properties | Applications |
| Magnesium AZ31B | A 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.
| Grade | Properties | Applications |
| Inconel 718 | Austenitic 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 36 | Nickel-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 |
| Kovar | Expand 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.
| Grade | Properties | Applications |
| Zamak 3 | Contains 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！
