Common Metal Materials for Desktop CNC Machining

1.Soft Metals

1.1 Aluminum Alloy: AL6061, AL6063, AL7075

6xxx aluminum alloy has magnesium as the main alloying element and is strengthened by the Mg2Si phase. 7xxx aluminum alloy is an aluminum alloy with zinc as the main alloying element.


  1. Low density, approximately 2.7g/cm³, about 1/3 of iron or copper.
  2. High strength, comparable to or exceeding high-quality steel.
  3. Good electrical and thermal conductivity, second only to silver and copper.
  4. Good corrosion resistance, with a naturally formed dense and strong Al2O3 protective film on the surface.
  5. Good plasticity, can be processed into various profiles. Disadvantages:
  6. Aluminum alloy has low hardness, large thermal deformation, and relatively poor wear resistance.
  7. The rigidity-to-weight ratio of aluminum alloy is 1/3 of that of steel.
1.1.2 AL6061

It is one of the most commonly used aluminum alloy materials, lightweight, easy to process, and cost-effective. It can be the preferred choice when mechanical strength requirements are not high.

DensityYield StrengthTensile StrengthElongation
2.75g/cm³≥110Mpa≥200MPa ≥16%
1.1.2 AL6063

Superior extrudability, it is a typical extrusion alloy that can form various cross-sectional shapes. It has excellent corrosion resistance and surface treatment performance, commonly used in profiles.

DensityYield StrengthTensile StrengthElongation
2.69g/cm³≥170Mpa≥205MPa ≥9%
1.1.3 AL7075

It is one of the highest strength alloys in aluminum alloys, known as aerospace aluminum. It has good corrosion resistance and is a super hard aluminum alloy with high flatness and hardness.

DensityYield StrengthTensile StrengthElongation
2.81g/cm³≥455Mpa≥524MPa ≥11%
Q1: Difference between Al6061 and 6063, and how to choose?

Al6061 has a higher alloy content and better hardness, while Al6063 has better anodizing effect, better formability, and better heat dissipation.

Q2: What should be considered when CNC machining aluminum alloy?
  1. Choose suitable tools: Compared to steel, aluminum alloy has lower hardness but higher plasticity and thermal conductivity. Choosing the right tools such as high-speed steel tools, hard alloy tools, ceramic tools, etc., can improve processing efficiency and quality.
  2. Control machining parameters: Aluminum alloy has a low processing temperature and is prone to scratches, thermal deformation, etc. Therefore, it is necessary to control the machining parameters such as cutting speed, feed rate, cutting depth, etc., to ensure stability and efficiency during the machining process.
  3. Maintain appropriate lubrication conditions: To reduce tool wear and thermal damage to the workpiece surface, common lubrication methods include hydraulic oil, cutting fluids, etc.
Q3: Difference between 7075 and 6061?
  1. Different elements: 7075 mainly contains zinc, while 6061 mainly contains magnesium and silicon, so 7075 has higher strength.
  2. Different applications: 6061 is used for new energy vehicle bodies, ships, rail transportation, 3C products, fuel tanks, etc., where high strength, weldability, and corrosion resistance are required. 7075 is mainly used in aerospace, such as aircraft structural manufacturing, high-stress structural parts with high strength and corrosion

1.2 Copper Alloys: H59, H62

Common ones include brass, bronze, and white copper. Brass is generally used for general performance, white copper for high mechanical requirements, and purple copper for high electrical conductivity. Brass is mainly alloyed with zinc.

1.2.1 H59

Brass H59 contains 59% copper and is the cheapest brass. It has high strength, good hardness, and good plasticity but average corrosion resistance. It is commonly used in mechanical and electrical parts, stampings, instruments, radiators, etc. Equivalent to ASTM C28000 and JIS C2801.

DensityThermal ConductivityTensile StrengthElongation
1.2.2 H62

Brass H62 contains 62% copper and is a common brass. It has good hot plasticity, acceptable cold plasticity, good machinability, and is easy to solder and weld. It has corrosion resistance but is prone to corrosion cracking. Equivalent to ASTM C27400 and JIS C2720.

DensityThermal ConductivityTensile StrengthElongation

2.Hard Metals

2.1 Stainless Steel 304

304 stainless steel is one of the most commonly used stainless steels. It is known as 18/8 stainless steel, meaning it contains over 18% chromium and over 8% nickel. It has good high-temperature resistance (up to 800°C), excellent machinability, and high toughness. It is widely used in industries such as industrial, furniture decoration, and food and medical fields. It is commonly labeled as 06Cr19Ni10 (international standard), 304 (ASTM standard), and SUS 304 (JIS standard).

DensityYield StrengthTensile StrengthElongationHardness
7.93g/cm³ ≥205Mpa≥515MPa ≥40%≤201HBW

2.2 45 Steel

45# is a high-quality carbon structural steel, corresponding to JIS S45C, ASTM 1045, and DIN C45. Compared to ordinary A3 steel, it has higher strength and deformation resistance. It has good machinability and mechanical properties and can be used as material for important load-bearing parts. Generally, it undergoes quenching and tempering to improve its mechanical properties. It can also be surface-treated with blackening or galvanizing to prevent rust.

DensityYield StrengthTensile StrengthElongationHardness
7.85g/cm³ ≥355Mpa≥600MPa ≥16% ≤197HB

2.3 Titanium Alloys TC4

Titanium alloys are metal alloys containing titanium and other chemical elements. They have superior mechanical properties, low density, excellent corrosion resistance, and high heat resistance. Titanium alloys have higher material and processing costs and are commonly used in aerospace, aerospace, and medical fields.

Titanium Alloy TC4: Composed of Ti-6Al-4V (Grade 5), it belongs to (α+β) type titanium alloy and has excellent comprehensive mechanical properties. It has higher strength and is commonly used in aerospace, medical, military, and industrial fields.

DensityYield StrengthTensile StrengthElongationHardness
4.43g/cm³ ≥800Mpa≥900MPa ≥10% ≥30HRC