Material selection matters. A lot. It directly influences performance, durability, and cost. Get it wrong and the part fails. Get it right and everything works.

Engineers and manufacturers face real decisions here. Lightweight plastics or high-strength metals? The choice determines how the part performs. This guide covers the most commonly used materials in CNC machining and where they fit.

Snapshot: Common CNC Machining Materials

Material Key Properties Common Applications Machinability
Aluminum (6061/7075) Lightweight, corrosion resistant Aerospace, automotive, electronics Excellent
Stainless Steel (304/316) Strong, corrosion resistant, heat resistant Medical, food processing, marine Moderate
Steel (1018/4140/A36) High strength, wear resistant Industrial machinery, automotive Good
Brass Low friction, aesthetic finish Plumbing, hardware, instruments Excellent
Titanium High strength-to-weight, biocompatible Aerospace, medical implants Difficult
ABS Plastic Lightweight, impact resistant Prototypes, enclosures Excellent
Nylon Wear resistant, low friction Gears, bushings, moving parts Good
Delrin (Acetal) High stiffness, dimensionally stable Bearings, precision components Excellent
Polycarbonate Transparent, impact resistant Safety equipment, optical parts Good
PTFE (Teflon) Chemical resistant, non-stick Seals, electrical insulation Moderate

Metals: Strength, Durability, and Versatility

Aluminum

Aluminum is one of the most popular CNC machining materials. Easy to machine. Lightweight. Corrosion resistant. Hard to beat for general-purpose work.

Widely used in aerospace, automotive, and electronics. Aluminum 6061 and 7075 are the most common grades. Good balance of strength and workability.

Typical applications? Aircraft parts. Engine components. Housings. Brackets. If you need something light that won’t rust, aluminum is usually the answer.

Stainless Steel

Strong. Corrosion resistant. Looks good too. Stainless steel handles high-stress and harsh environments better than most materials.

Grades 304 and 316 show up in food processing, medical devices, and marine equipment. Harder to machine than aluminum. Takes longer. Costs more. But the durability and thermal resistance are worth it for the right applications.

Steel and Alloy Steel

Steel provides excellent strength and wear resistance. Carbon steel. Alloy steel. Different grades for different jobs.

Commonly used in industrial machinery, automotive frames, and structural components. Popular grades include 1018, 4140, and A36. Each offers different hardness and machinability levels.

Heat-treated alloy steels are particularly valuable for high-performance mechanical parts. When something needs to take a beating, steel usually delivers.

Brass

Brass is a copper-zinc alloy. Easy to machine. Low friction. Machines beautifully.

Shows up in plumbing fittings, musical instruments, and decorative hardware. CNC-machined brass parts often get chosen for aesthetic finish and antimicrobial properties.

Not the strongest option. But for the right application, nothing else looks or performs quite like it.

Titanium

Titanium is special. High strength-to-weight ratio. Excellent corrosion resistance. Biocompatible.

Challenging to machine though. Expensive too. But aerospace, medical implants, and high-performance automotive applications demand it.

Surgical and dental applications rely on titanium’s biocompatibility. The human body tolerates it well. That matters when you’re putting something inside a person.

Plastics: Lightweight and Cost-Effective Solutions

ABS (Acrylonitrile Butadiene Styrene)

ABS is lightweight and impact-resistant. Common in prototyping, consumer products, and enclosures.

Easy to machine. Good dimensional stability. Go-to choice for cost-effective, low-strength applications.

Not for heavy loads or high temps. But for prototypes and housings? Works great.

Nylon

Nylon is strong and wear-resistant. Good chemical resistance. Flexible.

Used in gears, bushings, and industrial parts. Low friction and high impact strength make it ideal for mechanical assemblies and moving parts.

Anywhere you need something that slides or rotates without wearing out fast, nylon is worth considering.

Delrin (Acetal)

Delrin offers high stiffness and low friction. Excellent dimensional stability.

Often used for precision components. Bearings. Rollers. Valve parts. Anywhere tight tolerances matter.

Low moisture absorption is a bonus. Delrin stays stable in conditions that would swell other plastics.

Polycarbonate

Polycarbonate is transparent. Impact resistant. Heat resistant.

Used in safety equipment, light covers, and optical components. CNC machining provides clean edges while maintaining clarity.

When you need something you can see through that won’t shatter on impact, polycarbonate is the material.

PTFE (Teflon)

PTFE is non-stick and chemically inert. Used in electrical insulation, chemical handling, and sealing components.

Soft though. Prone to deformation under load. But thermal stability and chemical resistance are excellent.

Harsh chemical environments that would destroy other materials? PTFE handles them.

Matching Materials to Applications

Selecting the right material depends on several factors. Part function. Operating environment. Desired mechanical properties.

Mechanical Requirements

Load-bearing capacity. Wear resistance. Flexibility. What does the part actually need to do?

Environmental Conditions

Exposure to heat? Moisture? Chemicals? UV light? The environment determines which materials survive.

Machinability

Ease of cutting. Tool wear. Processing time. Some materials machine fast and cheap. Others don’t.

Cost and Availability

Material cost. Lead time. Sourcing considerations. Budget matters. So does getting material when you need it.

Engineers and product designers must balance these factors. No perfect material exists. Just trade-offs.

Working with an experienced CNC machining provider helps identify materials that meet both technical requirements and budget constraints.

FAQs

What is the best material for CNC machining?

Depends on the application. Aluminum is the most versatile for general-purpose work. Stainless steel for corrosion resistance. Titanium for strength-to-weight ratio. No single best material. Just the right one for your specific needs.

What metals can be CNC machined?

Most metals work with CNC. Aluminum, stainless steel, carbon steel, alloy steel, brass, copper, titanium, and more. Some machine easier than others. Aluminum is fast. Titanium is slow and expensive. But all are possible.

Is plastic or metal better for CNC machining?

Neither is universally better. Metals offer strength and durability. Plastics offer light weight and lower cost. Choose based on what the part needs to do. Load-bearing parts usually need metal. Housings and prototypes often work fine in plastic.

What is the easiest material to CNC machine?

Aluminum and brass are the easiest metals. ABS and Delrin are the easiest plastics. Fast cutting speeds. Low tool wear. Good surface finish without extra work.

How do I choose the right CNC material?

Consider four things. Mechanical requirements—what loads and stresses will it face? Environment—heat, chemicals, moisture? Machinability—how does it affect cost and lead time? Budget—what can you afford? Balance these factors against each other.

Why Styner Machine Tools

Material selection can be overwhelming. Hundreds of options. Countless trade-offs.

Styner Machine Tools helps customers navigate these decisions. We machine all the materials covered here—and more. Our team knows which materials work best for specific applications.

Bring us your design. We’ll help you pick the right material. Then we’ll machine it right.