BRIGHTSTAR
PROTOTYPE CNC CO., LTD
+86 137 5010 5351
EN
March. 25, 2026
Are you designing a part but unsure which material to choose from the many options available? Are you worried that choosing the wrong material might compromise part performance or exceed your budget? Do you want to understand which materials are best suited for CNC machining and which are difficult to machine or costly?
Material selection is one of the most critical decisions in any CNC machining project. Choose the right material, and your part will perform well, costs will be under control, and delivery will be smooth. Choose the wrong material, and you risk part failure, cost overruns, or even project cancellation.
This article systematically introduces the most commonly used metals and plastics for CNC machining, detailing the characteristics, typical applications, machining difficulty, and cost considerations for each material. It will help you make informed material selection decisions during the design phase.
Before selecting a CNC machining material, you need to understand the operating conditions and requirements your part will face. The following five factors are the core basis for material selection.
The mechanical performance of a part directly determines whether it can function properly under expected operating conditions.
Strength: What loads will the part need to withstand? Static loads or dynamic loads? Tensile strength and yield strength are key indicators. High-strength parts like aerospace structural components require materials such as 7075 aluminum alloy or titanium alloy, while ordinary brackets can be satisfied with 6061 aluminum alloy.
Hardness: Does the part surface need to be wear-resistant? Does it need to resist scratching and wear? Higher hardness means better wear resistance but also greater machining difficulty. Cutting tools and bearing parts require high-hardness materials such as 420 stainless steel or hardened alloy steel.
Toughness: Does the part need to resist impact? Will it be used in low-temperature environments? Tough materials are less likely to fracture. Automotive chassis components and outdoor equipment require tough materials such as nylon or low-carbon steel.
Elastic Modulus: Does the part need rigidity or flexibility? Higher elastic modulus means stiffer material; lower means more flexible. Precision instrument brackets require high-rigidity materials such as POM or aluminum alloy, while seals require low-modulus materials such as PTFE.
Fatigue Strength: Will the part endure cyclic loads? Fatigue strength determines the service life of a part. Engine components and spring parts require materials with excellent fatigue resistance such as 2024 aluminum alloy or beryllium copper.
Materials must be able to adapt to the various challenges presented by the part's operating environment.
Operating Temperature: What temperature range will the part operate in? High temperature, low temperature, or room temperature? Different materials have vastly different temperature resistance. High-temperature environments require PEEK (250°C) or superalloys (700°C), while low-temperature environments require tough materials like polycarbonate.
Corrosion: Will the part come into contact with water, chemicals, salt spray, acids, alkalis, or other corrosive media? Corrosion resistance directly affects part life. Marine equipment requires 316L stainless steel or titanium alloy, while chemical equipment requires PTFE or PEEK.
Outdoor Exposure: Does the part need UV resistance and weather resistance? Long-term outdoor use requires materials with good aging resistance. Outdoor equipment housings require PC with UV stabilizers or surface-treated aluminum alloy.
Sanitary Requirements: Does the part need to meet food contact standards or medical application standards? Food-grade and medical-grade materials have special requirements. Medical implants require titanium alloy or PEEK, while food equipment requires 304 stainless steel or FDA-approved plastics.
Electrical Conductivity/Insulation: Electronic parts have specific requirements for conductivity or insulation. Conductive parts require copper, brass, or aluminum alloy, while insulating parts require engineering plastics such as POM or ABS.
The machinability of a material directly affects machining cost, lead time, and finished part quality.
Cutting Performance: Is the material easy to machine? Free-cutting materials allow smooth machining, long tool life, and good surface finish. 303 stainless steel, brass, 6061 aluminum alloy, and POM are representative free-cutting materials.
Material Cost: What is the raw material price? Are there more economical alternatives? 6061 aluminum alloy and ABS plastic are low-cost, while titanium alloy and PEEK are expensive.
Machining Efficiency: How fast can the material be machined? Difficult-to-machine materials require slower cutting speeds, increasing machining time. Titanium alloy machining speed is about one-third that of aluminum alloy, while Inconel is even slower.
Tool Wear: How much does the material wear down cutting tools? High-wear materials require frequent tool changes, increasing costs. Titanium alloy and superalloys cause significant tool wear and require specialized cutting tools.
Special Equipment Required: Some difficult-to-machine materials require high-rigidity machines or special cooling systems. Machining titanium alloy requires high-rigidity machine tools and high-pressure cooling systems.
The final appearance and surface treatment requirements of the part are also important considerations for material selection.
Surface Finish: Does the part require a high-gloss surface? Some materials more readily achieve good surface finish. POM, brass, and 6063 aluminum alloy can achieve mirror finishes, while PTFE and nylon are more difficult to achieve high gloss.
Color: Does the part require a specific color? Colors can be achieved through anodizing, painting, plating, etc. Aluminum alloy can be anodized in various colors, while stainless steel can be plated in gold, black, etc.
Surface Treatment Compatibility: Does the material support the required surface treatment? Aluminum alloy can be anodized, stainless steel can be plated or passivated, and plastics like PEEK can be painted.
Texture: Does the part require a metallic texture, brushed finish, or matte finish? Brushed aluminum alloy, polished stainless steel, and vintage brass are common aesthetic requirements.
Certain industries have specific certification and standard requirements for materials.
Aerospace: Requires AS9100 certification, material traceability, and specific alloy grades such as 7075, 2024, Inconel, etc.
Medical: Requires ISO 13485 certification, biocompatibility certification (ISO 10993), and specific implant materials such as titanium alloy, PEEK, and cobalt-chromium-molybdenum alloy.
Food Industry: Requires FDA compliance and food contact material standards. Common materials include 304 and 316L stainless steel and food-grade plastics.
Electronics: Requires conductivity or insulation properties, and electromagnetic shielding performance. Common materials include copper, brass, aluminum alloy, ABS, and PC.
Defense: Has special material standards and certification requirements, requiring material traceability and quality certification.
Metal materials are the most commonly used category in CNC machining, widely applied in aerospace, medical, automotive, electronics, and other industries.
Aluminum alloys, with their light weight, high strength, corrosion resistance, and excellent machinability, are the most widely used metal materials in CNC machining.
6061 aluminum alloy is the most balanced aluminum alloy and the most commonly used material in CNC machining.
Material Properties: Excellent overall performance, moderate strength (tensile strength approximately 310MPa), good corrosion resistance, good weldability, and excellent machinability. It is the most versatile aluminum alloy grade, suitable for most applications.
Typical Applications: Structural components, housings, brackets, heat sinks, bicycle parts, mold bases, aerospace components, industrial equipment parts.
Machining Characteristics: Smooth cutting, long tool life, low tendency to stick to tools, good surface finish achievable, excellent anodizing results. Cutting speeds can reach 5000-8000 RPM with feed rates of 500-1000 mm/min.
Cost: Moderate, excellent value for money, the most economical aluminum alloy option. Material cost approximately $3-5 per kg.
7075 aluminum alloy is one of the strongest aluminum alloys, known as "aircraft aluminum."
Material Properties: Very high strength (tensile strength approximately 570MPa), close to steel but only one-third the weight of steel. Excellent fatigue resistance, but slightly lower corrosion resistance than 6061, poor weldability. Commonly used in high-stress applications.
Typical Applications: Aerospace structural components, high-performance racing parts, molds, firearm components, climbing equipment, drone components, high-end bicycle frames.
Machining Characteristics: Slightly more difficult to machine than 6061, requiring sharper tools and more appropriate cutting parameters. May experience stress deformation after machining; stress relief treatment recommended. Cutting speeds should be controlled at 3000-5000 RPM.
Cost: Higher, approximately 2-3 times the cost of 6061, material cost approximately $8-12 per kg, but offers superior performance.
6063 aluminum alloy is known for its excellent surface finishing characteristics.
Material Properties: Good extrusion properties, high surface finish, excellent anodizing results, slightly lower strength than 6061 (tensile strength approximately 240MPa). Particularly suitable for parts requiring good appearance.
Typical Applications: Heat sinks, housings, decorative parts, electronic device enclosures, window frames, tubing, furniture components.
Machining Characteristics: Easy to machine, excellent surface finish achievable, suitable for parts with high aesthetic requirements. Anodizing after machining yields uniform, attractive surface effects.
Cost: Moderate, similar to 6061, material cost approximately $3-5 per kg.
2024 aluminum alloy is known for its excellent fatigue resistance and is a traditional material in the aerospace field.
Material Properties: High strength (tensile strength approximately 470MPa), good fatigue resistance, but poor corrosion resistance, typically requiring cladding or surface treatment. Poor weldability.
Typical Applications: Aircraft structural components, rivets, high-stress components, aerospace parts, missile components.
Machining Characteristics: Good machinability, but requires stress control, prone to deformation after machining. Rough machining followed by stress relief treatment before finish machining is recommended.
Cost: Moderately high, material cost approximately $6-9 per kg.
5052 aluminum alloy is known for its excellent seawater corrosion resistance.
Material Properties: Excellent corrosion resistance, particularly seawater corrosion resistance, good weldability, moderate strength (tensile strength approximately 230MPa). Ideal for marine applications.
Typical Applications: Marine equipment, fuel tanks, pressure vessels, sheet metal parts, ship components, electronic device housings.
Machining Characteristics: Easy to machine, but relatively soft; thin-wall parts prone to deformation. Clamping force should be controlled to avoid part deformation.
Cost: Moderate, material cost approximately $3.5-5.5 per kg.
Application | Recommended Material | Reason |
General Structural Parts | 6061 | Best value, good all-around performance |
High-Stress Parts | 7075 | Highest strength |
Appearance Parts/Heat Sinks | 6063 | Best surface finish |
Aerospace Structural Parts | 2024, 7075 | High strength, fatigue resistance |
Marine Environment | 5052, 6061 | Good corrosion resistance |
Stainless steel, with its excellent corrosion resistance and good mechanical properties, has become the standard material in medical, food, chemical, and other industries.
304 stainless steel is the most commonly used austenitic stainless steel with an extremely wide range of applications.
Material Properties: Excellent corrosion resistance, good overall performance, non-magnetic, good machinability. Tensile strength approximately 515MPa, representative of general-purpose stainless steel.
Typical Applications: Food equipment, medical devices, chemical parts, architectural decoration, kitchenware, fasteners, water tanks.
Machining Characteristics: Significant work hardening, requires sharp tools and adequate coolant, cutting speeds should not be too high. Cobalt HSS or carbide tools recommended, cutting speed controlled at 60-80 m/min.
Cost: Moderate, best value stainless steel. Material cost approximately $2-3.5 per kg.
316L stainless steel is an upgraded version of 304 with superior corrosion resistance.
Material Properties: Contains molybdenum, corrosion resistance superior to 304, especially resistant to chloride corrosion (seawater). Good weldability, low carbon version reduces risk of intergranular corrosion. Tensile strength approximately 485MPa.
Typical Applications: Marine equipment, medical implants, chemical equipment, pharmaceutical equipment, food processing equipment, ship components.
Machining Characteristics: Slightly more difficult to machine than 304, requires more stringent process control, tends to generate heat during cutting. High-pressure cooling systems recommended, cutting speed controlled at 50-70 m/min.
Cost: Higher, material cost approximately $3-5 per kg.
17-4PH is a precipitation-hardening stainless steel with extremely high strength.
Material Properties: Precipitation-hardening stainless steel, extremely high strength, can achieve high hardness after heat treatment (HRC 40-45), good corrosion resistance. Tensile strength can reach 1000-1300MPa.
Typical Applications: Aerospace components, pump shafts, valve components, high-stress structural parts, molds, nuclear industry components.
Machining Characteristics: Easy to machine in annealed condition, difficult after heat treatment, requiring grinding or hard turning. Most machining should be completed before heat treatment, followed by finish grinding.
Cost: Higher, material cost approximately $5-8 per kg.
303 stainless steel is representative of free-cutting stainless steel.
Material Properties: Contains sulfur, free-cutting stainless steel, excellent machinability, but slightly lower corrosion resistance than 304. Tensile strength approximately 515MPa.
Typical Applications: Precision parts, screws, shafts, fittings, instrument parts, fasteners.
Machining Characteristics: Smooth cutting, good surface finish achievable, long tool life, suitable for high-volume precision machining. Cutting speeds can reach 80-100 m/min.
Cost: Moderate, material cost approximately $2.5-4 per kg.
420 stainless steel is a martensitic stainless steel with high hardness.
Material Properties: Martensitic stainless steel, high hardness, good wear resistance, can be heat treated to HRC 50 or above. Corrosion resistance lower than 300 series.
Typical Applications: Cutting tools, surgical instruments, bearings, molds, valve components, scissors.
Machining Characteristics: Machinable in annealed condition, requires grinding after heat treatment, sensitive to cutting parameters. Rough machining recommended in annealed condition, followed by finish grinding after heat treatment.
Cost: Moderate, material cost approximately $2.5-4 per kg.
Application | Recommended Material | Reason |
General Corrosive Environment | 304 | Best value, most widely used |
Marine/Highly Corrosive Environment | 316L | Chloride corrosion resistance |
High Strength Requirements | 17-4PH | Extremely high strength, heat treatable |
Complex Precision Parts | 303 | Free-cutting, good machinability |
Cutting Tools/Edges | 420 | High hardness, good wear resistance |
Titanium alloys, with their excellent strength-to-weight ratio and superior corrosion resistance, are the preferred materials in aerospace, medical, and high-end consumer product fields.
TC4 is the most widely used titanium alloy, known as "aerospace titanium."
Material Properties: High strength (tensile strength approximately 900-1000MPa), density approximately 60% of steel (4.43g/cm³), excellent corrosion resistance, good biocompatibility. Excellent overall performance.
Typical Applications: Aerospace structural components, medical implants, racing parts, high-end watches, bicycle frames, golf club heads, deep-sea equipment.
Machining Characteristics: Difficult to machine, poor thermal conductivity, cutting heat concentrated, rapid tool wear, requires high-rigidity machine tools and specialized cutting parameters. Cutting speed recommended at 30-50 m/min with high-pressure cooling systems.
Cost: High, both material and machining costs are high. Material cost approximately $20-40 per kg.
TA2 is commercially pure titanium with good plasticity.
Material Properties: High purity, excellent corrosion resistance, good plasticity, lower strength than TC4 (tensile strength approximately 400MPa). Density 4.5g/cm³.
Typical Applications: Chemical equipment, medical implants, heat exchangers, ship components, human implants.
Machining Characteristics: Easier to machine than TC4, but still has tendency to stick to tools, requires sharp tools and adequate cooling. Cutting speed recommended at 40-60 m/min.
Cost: Higher, material cost approximately $15-30 per kg.
High Strength Requirements: Choose TC4 (Ti6Al4V), high strength, suitable for structural parts.
High Plasticity/High Corrosion Resistance Requirements: Choose TA2, good plasticity, suitable for parts requiring forming.
Important Notes: Titanium alloy machining requires suppliers with specialized experience and equipment. High-rigidity machine tools, specialized carbide tools, and high-pressure cooling systems are necessary.
Carbon steel and alloy steel, with their good overall performance and low cost, are widely used in general mechanical part manufacturing.
45# steel is the most commonly used medium carbon steel with wide applications.
Material Properties: Good overall performance, low cost, heat treatable for increased hardness. Tensile strength approximately 600MPa, can reach HRC 40-45 after heat treatment.
Typical Applications: Shafts, gears, connectors, tooling fixtures, mold bases, general mechanical parts.
Machining Characteristics: Good machinability, more difficult after heat treatment, requiring grinding. Rough machining recommended in annealed condition, followed by finish grinding after heat treatment.
Cost: Low, material cost approximately $0.5-1 per kg.
Q235 steel is low-carbon steel with good weldability.
Material Properties: Low-carbon steel, good plasticity, good weldability, low cost, lower strength (tensile strength approximately 375MPa). Most common structural steel.
Typical Applications: Structural components, welded parts, brackets, frames, bases.
Machining Characteristics: Easy to machine, but surface finish not as good as other materials, tendency to produce burrs. Suitable for welded structures and parts not requiring high precision.
Cost: Low, material cost approximately $0.4-0.8 per kg.
40Cr and 42CrMo are commonly used alloy structural steels with high strength.
Material Properties: Alloy structural steel, good hardenability, high strength, good wear resistance, excellent overall mechanical properties. 42CrMo has higher strength, tensile strength exceeding 1000MPa.
Typical Applications: High-strength shafts, gears, connecting rods, molds, transmission components.
Machining Characteristics: Easy to machine in annealed condition, high hardness after quenching, requiring grinding or hard turning. Rough machining recommended before heat treatment.
Cost: Moderate, material cost approximately $1-2 per kg.
Copper and its alloys, with their excellent electrical and thermal conductivity and corrosion resistance, are widely used in electronics, electrical, and heat dissipation fields.
Brass is a copper-zinc alloy with excellent machinability.
Material Properties: Free-cutting, good electrical conductivity, golden appearance, good corrosion resistance, good self-lubricating properties. Moderate strength, tensile strength approximately 300-400MPa.
Typical Applications: Connectors, valves, decorative parts, precision parts, instrument parts, fittings.
Machining Characteristics: Extremely easy to machine, excellent surface finish achievable, long tool life, suitable for high-volume precision machining. Cutting speeds can reach 200-300 m/min.
Cost: Moderate, material cost approximately $4-6 per kg.
Red copper is pure copper with excellent electrical and thermal conductivity.
Material Properties: Excellent electrical conductivity (second only to silver), excellent thermal conductivity, good plasticity, but relatively soft. Electrical conductivity up to 98% IACS, thermal conductivity approximately 400 W/m·K.
Typical Applications: Conductive parts, heat sinks, electrodes, high-frequency equipment, electronic components, transformer windings.
Machining Characteristics: Soft, tendency to stick to tools, requires sharp tools and adequate cooling, difficult to achieve high surface finish. Cutting speed recommended at 100-150 m/min.
Cost: Higher, material cost approximately $6-9 per kg.
Beryllium copper is a copper-beryllium alloy with excellent spring properties.
Material Properties: Excellent spring properties, good wear resistance, good fatigue resistance, high strength, good electrical conductivity. Can achieve HRC 38-42 after heat treatment.
Typical Applications: Springs, connectors, precision instrument parts, molds (injection mold inserts), contacts.
Machining Characteristics: Moderate machining difficulty, very high strength after heat treatment, requires attention to machining stress. Most machining recommended before heat treatment.
Cost: High, material cost approximately $20-40 per kg.
Engineering plastics, with their unique advantages of light weight, insulation, and corrosion resistance, play an irreplaceable role in many industries.
PEEK (Polyether Ether Ketone) is one of the most outstanding engineering plastics, widely used in high-end manufacturing.
Material Properties:
· High temperature resistance: Long-term service temperature up to 250°C, short-term up to 300°C
· Chemical resistance: Resistant to almost all chemicals, only soluble in concentrated sulfuric acid
· High strength: Tensile strength approximately 90-100MPa, one of the strongest plastics
· Wear resistance: Excellent, suitable for sliding components, low coefficient of friction
· Biocompatibility: Suitable for medical implants, compliant with ISO 10993
· Dimensional stability: Excellent, low coefficient of thermal expansion
· Flame retardancy: UL94 V-0 rated
Typical Applications: Medical implants, surgical instruments, aerospace components, semiconductor equipment, petrochemical parts, high-temperature electronic components, bearings, seals.
Machining Characteristics: Moderately difficult to machine, requires sharp tools and adequate cooling, good dimensional stability, not prone to deformation. Carbide tools recommended, cutting speed at 100-200 m/min with adequate cooling.
Cost: Very high, among the most expensive engineering plastics. Material cost approximately $80-150 per kg.
PTFE (Polytetrafluoroethylene) is known for its extremely low coefficient of friction and excellent corrosion resistance.
Material Properties:
· Extremely low coefficient of friction: Lowest among solid materials (approximately 0.04)
· Chemical resistance: Resistant to almost all chemicals
· High temperature resistance: Long-term service temperature up to 260°C
· Non-stick properties: Almost nothing adheres to it
· Electrical insulation: Excellent, high dielectric strength
· Low temperature performance: Usable down to -180°C
Typical Applications: Seals, bearings, insulating parts, non-stick coatings, chemical piping, gaskets, high-frequency electronic components.
Machining Characteristics: Soft material, prone to deformation, requires special clamping methods, poor dimensional stability, requires machining allowance. Sharp tools recommended, reduce clamping force, dimensions may spring back after machining.
Cost: Higher, material cost approximately $8-15 per kg.
ABS is the most widely used general engineering plastic, with balanced overall performance and low cost.
Material Properties:
· Balanced overall performance, moderate strength (tensile strength approximately 40-50MPa)
· Good toughness, excellent impact resistance
· Can be plated, painted, and silk-screened
· Good dimensional stability
· Temperature resistance approximately 80-100°C
Typical Applications: Electronic product housings, automotive interior parts, toys, prototypes, appliance components, office equipment.
Machining Characteristics: Easy to machine, smooth cutting, good surface finish, low tendency to produce burrs. High machining speeds, cutting speed up to 200-300 m/min.
Cost: Low, material cost approximately $1.5-3 per kg.
PC is the preferred material for transparent parts due to its high transparency and excellent impact resistance.
Material Properties:
· High transparency: Light transmittance close to glass (approximately 89%)
· High strength: Excellent impact resistance, known as "bulletproof glass," tensile strength approximately 60-70MPa
· Temperature resistance: Service temperature up to 120°C
· Good dimensional stability
· Good weather resistance, but UV stabilizers needed for long-term outdoor use
Typical Applications: Transparent housings, protective covers, lamp lenses, eyeglass lenses, safety windows, water bottles, optical discs.
Machining Characteristics: Easy to machine, but requires attention to stress cracking, can be polished to optical clarity. Annealing recommended after machining to relieve internal stress.
Cost: Moderate, material cost approximately $2.5-4.5 per kg.
POM is the preferred material for precision mechanical parts due to its excellent dimensional stability and wear resistance.
Material Properties:
· High strength, good rigidity (tensile strength approximately 60-70MPa)
· Excellent dimensional stability, not prone to deformation
· Excellent wear resistance, good self-lubricating properties
· Good fatigue resistance
· Temperature resistance approximately 80-100°C
Typical Applications: Precision gears, bearings, sliders, valve components, conveyor parts, fixtures, fasteners, rollers.
Machining Characteristics: Extremely easy to machine, high dimensional accuracy, good surface finish, long tool life. High machining speeds, high precision achievable.
Cost: Moderate, material cost approximately $2-4 per kg.
Nylon is widely used for sliding components and wear parts due to its excellent wear resistance and toughness.
Material Properties:
· Excellent wear resistance
· Good toughness, good impact resistance
· Good self-lubricating properties
· Significant moisture absorption, requires attention to dimensional changes (dimensions increase after moisture absorption)
· Temperature resistance approximately 80-100°C
Typical Applications: Gears, pulleys, guides, bushings, wear parts, cable ties, tool handles.
Machining Characteristics: Good machinability, but dimensions may change after moisture absorption; operating environment must be considered. Machining recommended in dry condition, allowance for moisture absorption expansion should be considered in design.
Cost: Low to moderate, material cost approximately $1.5-3 per kg.
Acrylic is the preferred material for display and decorative parts due to its extremely high transparency and good aesthetic appearance.
Material Properties:
· High transparency, light transmittance up to 92%, better than ordinary glass
· Good surface hardness, good weather resistance
· Relatively brittle, poor impact resistance
· Easy to machine and polish
· Temperature resistance approximately 70-80°C
Typical Applications: Transparent panels, display cases, lamp covers, decorative parts, signage, aquariums, optical lenses.
Machining Characteristics: Easy to machine, but prone to cracking, requires sharp tools, can be polished to optical clarity. Avoid overheating during machining to prevent cracking.
Cost: Low to moderate, material cost approximately $1.5-3 per kg.
Application | Recommended Material | Reason |
High-End High-Temperature Parts | PEEK | Best performance, 250°C temperature resistance |
Seals/Bearings | PTFE | Extremely low friction, corrosion resistant |
General Housings/Prototypes | ABS | Good value, easy to machine |
Transparent Parts | PC, Acrylic | High transparency, PC has better toughness |
Precision Gears/Sliders | POM | Dimensional stability, good wear resistance |
Wear Sliding Parts | Nylon | Good wear resistance, moderate cost |
For specific high-end applications, the following special materials, while difficult to machine, offer exceptional performance.
Superalloys are critical materials for the aerospace and energy industries.
Material Properties:
· High temperature resistance up to 700°C or higher
· Excellent corrosion resistance
· High strength, good oxidation resistance
· Severe work hardening
Typical Applications: Aircraft engine components, gas turbines, chemical equipment, nuclear industry, rocket engines.
Machining Characteristics: Extremely difficult to machine, rapid tool wear, requires high-rigidity machine tools, specialized cutting tools, and strict process control. Cutting speed typically 20-30 m/min with high-pressure cooling systems.
Cost: Very high, material cost approximately $20-60 per kg.
Engineering ceramics are known for their extremely high hardness and wear resistance.
Material Properties:
· Extremely high hardness, excellent wear resistance
· High temperature resistance, good insulation
· Brittle, prone to fracture
· Good dimensional stability
Typical Applications: Wear parts, insulating components, medical implants, cutting tools, bearings, seal rings.
Machining Characteristics: Requires specialized grinding or laser processing equipment; cannot be machined with traditional CNC cutting tools. Diamond grinding wheels required.
Cost: High, both material and machining costs are high.
Composites are widely used in high-end fields due to their light weight and high strength.
Material Properties:
· Light weight and high strength, excellent strength-to-weight ratio
· Anisotropic, properties vary with fiber direction
· Good fatigue resistance
· Highly designable
Typical Applications: Aerospace structural components, racing parts, sporting goods, drone components, wind turbine blades.
Machining Characteristics: Requires specialized tools to avoid delamination and burrs, machining generates dust. Diamond-coated tools recommended with dust extraction during machining.
Cost: High, both material and machining costs are high.
Here are the most common questions customers ask during material selection, answered in advance.
For metals, 6061 aluminum alloy is the most commonly used due to its excellent overall performance, good machinability, and high value for money, suitable for most general structural parts. For plastics, ABS and POM are the most common; ABS is suitable for housings, while POM is suitable for precision functional parts.
For metals: 6061 aluminum alloy, 303 stainless steel, and brass. These materials cut smoothly, have long tool life, and relatively low machining costs. For plastics: ABS, POM, and nylon. These materials are easy to machine, achieve good surface finish, and have low tendency to produce burrs.
For metals: Titanium alloy (TC4), superalloys (Inconel), and hardened high-hardness steel (HRC > 50). For plastics: PTFE (too soft, prone to deformation) and UHMWPE (prone to deformation). These materials require specialized equipment and processes, resulting in higher machining costs. Suppliers with relevant experience are recommended.
Application | Recommended Material | Reason |
General Parts, Structural Parts | 6061 | Best value |
High Strength Requirements | 7075 | Highest strength |
Appearance Parts, Heat Sinks | 6063 | Best surface finish |
| Aerospace High-Stress Parts
| 2024 | Good fatigue resistance |
Marine Environment | 5052 | Seawater corrosion resistance |
Application | Recommended Material | Reason |
General Corrosive Environment | 304 | Best value |
Marine/Highly Corrosive Environment | 316L | Chloride corrosion resistance |
High Strength Requirements | 17-4PH | Extremely high strength |
Complex Precision Parts | 303 | Free-cutting, good machinability |
Cutting Tools/Edges | 420 | High hardness |
PEEK has the following core advantages:
· High temperature resistance: Long-term service temperature 250°C
· Chemical resistance: Resistant to almost all chemicals
· High strength: Strength close to metal
· Biocompatibility: Suitable for medical implants
· Excellent wear resistance
Scenarios for choosing PEEK: Medical implants and surgical instruments, aerospace high-temperature components, semiconductor equipment parts, petrochemical corrosion-resistant components, parts requiring high strength at high temperatures.
The proportion of material cost varies by material:
· Common materials (aluminum alloy, ABS): Material cost typically accounts for 10-30% of total cost
· Premium materials (titanium alloy, PEEK, Inconel): Material cost may account for 50-70% of total cost
Reasonable material selection can effectively control total project cost. Sometimes using a slightly more expensive free-cutting material can actually reduce overall machining cost.
Yes. Brightstar accepts customer-supplied materials, especially for:
· Special alloys with specific certification requirements
· Projects requiring specific batch numbers for aerospace applications
· Customer-owned premium materials
Please communicate material information and machining requirements in advance to ensure the material is suitable for CNC machining.
Requirement | Recommended Material Type | Reason |
High Strength, High Temperature | Metal | Metal has higher strength, better temperature resistance |
Lightweight | Plastic or Aluminum Alloy
| Plastic has low density, aluminum has good strength-to-weight ratio |
Conductivity | Metal | Metal conducts electricity, plastic insulates |
Transparency | Plastic (PC, Acrylic) | Metal is opaque |
Corrosion Resistance | Stainless Steel, Titanium, PEEK | All have good corrosion resistance |
Low Cost, High Volume | Plastic | Low material cost, high machining efficiency |
Send your part drawings to Brightstar, and our engineers will provide professional material selection recommendations and free DFM analysis based on:
· Application scenarios and operating conditions
· Mechanical performance requirements (strength, hardness, toughness, etc.)
· Budget and quantity requirements
· Surface finish requirements
Brightstar offers free DFM (Design for Manufacturability) evaluation services. When you send us your drawings, our engineers will:
· Analyze your part drawings and evaluate the rationality of material selection
· Provide alternative material recommendations to optimize cost and performance
· Identify potential machining risks in the design
· Provide process optimization recommendations
For high-end industries such as aerospace and medical, material certification is critical. Brightstar provides:
· Complete material certification services, including material certificates and heat treatment reports
· Support for material traceability requirements for aerospace, medical, and other industries
· Material management compliant with AS9100 and ISO 13485 standards
· Partnerships with multiple quality material suppliers to ensure reliable material sources
Brightstar provides one-stop services including material sourcing, CNC machining, and surface finishing:
· Partnerships with multiple quality material suppliers to ensure material quality
· Bulk purchasing according to your requirements to reduce material costs
· Eliminates the hassle of coordinating with multiple vendors; one point of contact, complete service
Choosing the right CNC machining material is a critical step in project success. Material not only determines part performance and service life but also directly affects machining cost, lead time, and feasibility. This article systematically introduces the most commonly used metals and plastics for CNC machining, including aluminum alloys, stainless steel, titanium alloys, carbon steel, copper alloys, PEEK, PTFE, ABS, PC, POM, nylon, and acrylic, helping you make informed material selection decisions during the design phase.
Get Free Material Selection Consultation Now
Send your drawings to Brightstar, and our engineers will provide you with:
· Professional material selection recommendations
· Process feasibility analysis
· Cost optimization suggestions
· Free DFM evaluation
· Relevant industry case references
Contact Information
Phone / WeChat: +86-13750105351
Email: amy@brightstarprototype.com
Website: www.brightstarprototype.com
Online Chat: Click the chat window in the bottom right corner to upload your drawings directly.
Brightstar is a professional CNC machining service provider specializing in high-precision, high-quality precision part machining for global clients. We have:
· 3-axis, 4-axis, and 5-axis CNC machining centers
· ISO 9001:2015 quality management system certification
· Extensive material machining experience covering aluminum alloys, stainless steel, titanium alloys, PEEK, and more
· Professional DFM technical support team
Whether your project belongs to aerospace, medical, automotive, robotics, electronics, or consumer goods industries, Brightstar is committed to being your reliable manufacturing partner.
Contact us today and bring your designs to life—fast.
