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Material Selection Guide

A comprehensive guide to choosing the right material for your manufacturing project. Compare properties, understand trade-offs, and make informed decisions backed by 25+ years of engineering expertise.

Overview Categories Metals Plastics Comparison Selection Process By Industry FAQ
Why Material Matters

Choosing the Right Material Is Critical

The material you select directly impacts your part's performance, cost, manufacturability, and lifespan. At MetalCore, we've helped over 500 clients navigate the complex material landscape to find the optimal solution for their specific application.

This guide covers the most commonly used manufacturing materials, their mechanical properties, ideal applications, and cost considerations. Whether you're prototyping a new product or scaling to full production, understanding your material options is the first step toward success.

Key factors we consider: mechanical strength, corrosion resistance, thermal properties, weight, cost per part, machinability, and regulatory compliance requirements.

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Mechanical Properties

Strength, hardness, ductility & more

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Thermal Behavior

Conductivity, expansion & resistance

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Cost Analysis

Raw material & processing costs

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Weight & Density

Specific gravity & weight savings

Material Categories

Explore Material Families

We work with six primary material families. Each offers unique advantages for different applications and manufacturing processes.

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Steel Alloys

High strength, excellent machinability, and cost-effective for structural applications.

12+ Grades Available
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Aluminum Alloys

Lightweight, corrosion-resistant, and ideal for aerospace and automotive components.

8+ Grades Available
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Titanium

Exceptional strength-to-weight ratio with outstanding corrosion resistance.

4+ Grades Available
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Engineering Plastics

Chemical resistance, electrical insulation, and design flexibility for complex geometries.

15+ Types Available
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Superalloys

Extreme temperature performance for aerospace, energy, and chemical processing.

6+ Grades Available
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Copper & Brass

Superior thermal/electrical conductivity for electronics, plumbing, and heat exchangers.

10+ Types Available
Metal Materials

Steel, Aluminum, Titanium & More

Metals remain the backbone of precision manufacturing. Below you'll find detailed profiles of the materials we stock and machine most frequently. Click any material to expand full property data, advantages, and recommended applications.

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304 / 304L Stainless Steel

Austenitic Stainless • Most Versatile Grade

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Tensile Strength
515 MPa
Yield Strength
215 MPa
Hardness
223 HB
Density
8.0 g/cm³
Food & Beverage Medical Chemical CNC Machining Welding

304 stainless steel is the most widely used austenitic stainless steel. It offers excellent corrosion resistance, good formability, and ease of cleaning — making it the default choice for food processing, pharmaceutical, and general industrial applications.

304L is the low-carbon variant, recommended for welded assemblies to prevent sensitization and intergranular corrosion.

✓ Excellent corrosion resistance
✓ Good weldability
✓ Non-magnetic (annealed)
✓ FDA compliant
✓ Wide temperature range
✓ Cost-effective for stainless
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6061-T6 Aluminum

Aluminum-Magnesium-Silicon • Most Popular Alloy

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Tensile Strength
310 MPa
Yield Strength
276 MPa
Hardness
95 HB
Density
2.7 g/cm³
Aerospace Automotive Consumer CNC Machining Anodizing

6061-T6 is the go-to aluminum alloy for CNC machining. It offers an excellent balance of strength, corrosion resistance, and machinability. The T6 temper (solution heat-treated and artificially aged) provides the best mechanical properties for structural applications.

At only 2.7 g/cm³, it provides roughly one-third the weight of steel while maintaining adequate strength for most non-structural-critical applications. Excellent for enclosures, brackets, heat sinks, and lightweight frames.

✓ Excellent machinability
✓ 1/3 the weight of steel
✓ Natural corrosion resistance
✓ Great for anodizing
✓ Good weldability
✓ Cost-effective aluminum
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Ti-6Al-4V (Grade 5) Titanium

Titanium Alloy • Premium Strength-to-Weight

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Tensile Strength
950 MPa
Yield Strength
880 MPa
Hardness
334 HB
Density
4.43 g/cm³
Aerospace Medical Implants Military 5-Axis CNC EBM/SLM

Ti-6Al-4V is the most widely used titanium alloy, accounting for over 50% of all titanium usage. It delivers exceptional strength-to-weight ratio — nearly twice as strong as aluminum at only 65% of the weight of steel.

Its outstanding biocompatibility makes it the gold standard for orthopedic implants, while its corrosion resistance and high-temperature performance make it indispensable in aerospace engines and chemical processing. Note: titanium is 4-6x more expensive than aluminum per part due to material cost and slower machining rates.

✓ Exceptional strength-to-weight
✓ Biocompatible (implant grade)
✓ Superior corrosion resistance
✓ High-temperature stable
✓ Low thermal expansion
✓ Non-magnetic
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17-4PH Stainless Steel

Precipitation Hardening • High-Strength Stainless

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Tensile Strength
1310 MPa
Yield Strength
1090 MPa
Hardness
388 HB
Density
7.8 g/cm³
Aerospace Marine Oil & Gas CNC Machining Heat Treatment

17-4PH (also known as 630) is a precipitation-hardening martensitic stainless steel that can be aged to reach very high strength levels while retaining good corrosion resistance. It's the go-to choice when you need stainless steel properties but with significantly higher strength than 304 or 316.

Common applications include valve components, pump shafts, aerospace fittings, and surgical instruments where both strength and corrosion resistance are critical.

✓ Very high strength
✓ Good corrosion resistance
✓ Excellent machinability
✓ Age-hardenable
✓ Good fatigue resistance
✓ Retains strength at elevated temps
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Inconel 718 Superalloy

Nickel-Chromium-Molybdenum • Extreme Performance

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Tensile Strength
1295 MPa
Yield Strength
1195 MPa
Max Temp
700 °C
Density
8.19 g/cm³
Aerospace Engines Gas Turbines Nuclear 5-Axis CNC Investment Casting

Inconel 718 is a nickel-chromium-molybdenum superalloy capable of withstanding extreme temperatures up to 700°C while maintaining exceptional strength and creep resistance. It's one of the most challenging materials to machine but is indispensable for turbine blades, combustor components, and exhaust system parts.

Due to its difficulty to machine (work-hardens rapidly), Inconel 718 parts typically cost 5-10x more than equivalent steel parts. However, for applications where failure is not an option, the investment is justified.

✓ Extreme temperature resistance
✓ Outstanding creep resistance
✓ Oxidation resistant
✓ Excellent fatigue life
✓ Maintains strength at red heat
✓ Proven in aerospace service
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12L14 Free-Cutting Steel

Lead-Free Free-Machining • Best CNC Performance

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Tensile Strength
425 MPa
Yield Strength
360 MPa
Machinability
100 %
Density
7.85 g/cm³
Automotive Industrial Consumer CNC Turning High-Speed CNC

12L14 is the benchmark for free-cutting steels. Sulfur and selenium additions create chip-breaking properties that enable extremely fast machining speeds, long tool life, and excellent surface finishes. It's the most cost-effective material for high-volume CNC production.

Ideal for screws, bolts, shafts, bushings, and precision fasteners where corrosion resistance is not a primary concern. Often finished with plating (zinc, nickel) or paint for added protection.

✓ Fastest machining speed
✓ Longest tool life
✓ Lowest cost per part
✓ Excellent surface finish
✓ Consistent properties
✓ Easy to plate/finish
Engineering Plastics

High-Performance Polymers

Engineering plastics offer unique advantages including chemical resistance, electrical insulation, lightweight construction, and the ability to achieve complex geometries that would be impossible or cost-prohibitive with metals.

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Nylon 6 / Nylon 66

Polyamide (PA)

Strong, tough engineering thermoplastic with excellent wear resistance. Ideal for gears, bearings, and structural components.

Tensile Strength 80-100 MPa
Temp Range -40°C to 120°C
Density 1.14 g/cm³
Processes CNC, Injection
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Acetal (POM)

Delrin / Polyoxymethylene

High-stiffness, low-friction thermoplastic known for dimensional stability. Excellent for precision gears, slides, and connectors.

Tensile Strength 65-75 MPa
Temp Range -30°C to 100°C
Density 1.41 g/cm³
Processes CNC, Injection
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Polycarbonate (PC)

Amorphous Thermoplastic

Transparent, impact-resistant thermoplastic with excellent dimensional stability. Used for safety shields, lenses, and enclosures.

Tensile Strength 65-70 MPa
Temp Range -40°C to 135°C
Density 1.20 g/cm³
Processes CNC, Injection
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PEEK

Polyetheretherketone

Ultra-high-performance thermoplastic with exceptional chemical and thermal resistance. Used in aerospace, medical, and oil & gas.

Tensile Strength 95-100 MPa
Temp Range -260°C to 260°C
Density 1.32 g/cm³
Processes CNC, Injection
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PTFE (Teflon)

Polytetrafluoroethylene

The ultimate non-stick material with the lowest coefficient of friction. Chemical inert and operates from cryogenic to 260°C.

Tensile Strength 20-30 MPa
Temp Range -200°C to 260°C
Density 2.15 g/cm³
Processes CNC, Machining
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ABS

Acrylonitrile Butadiene Styrene

Versatile, cost-effective thermoplastic with good impact resistance. Ideal for prototyping, enclosures, and consumer products.

Tensile Strength 40-50 MPa
Temp Range -20°C to 80°C
Density 1.04 g/cm³
Processes CNC, 3D Print
Side-by-Side Comparison

Material Property Comparison

Compare key properties across popular manufacturing materials to find the best fit for your application requirements.

Material Tensile (MPa) Yield (MPa) Density (g/cm³) Corrosion Machinability Cost Index
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304 Stainless
515 215 8.0
9
6
Medium
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6061-T6 Aluminum
310 276 2.7
8
9
Low
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Ti-6Al-4V
950 880 4.43
10
4
Very High
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Inconel 718
1295 1195 8.19
10
2
Very High
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17-4PH Stainless
1310 1090 7.8
8
7
High
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12L14 Steel
425 360 7.85
3
10
Low
Decision Guide

Material Selection Process

Follow this step-by-step framework to narrow down your material options based on your application requirements.

1

Define Primary Requirements

What are the most critical factors for your application? Choose the dominant priority:

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Strength

Load-bearing, structural, high-stress applications

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Lightweight

Weight-sensitive, aerospace, portable devices

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Corrosion Resist.

Marine, chemical, food, medical environments

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2

Operating Environment

What conditions will the part be exposed to?

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High Temperature

Above 150°C — consider Inconel, ceramics, or high-temp alloys

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Standard / Ambient

Room temperature — widest material selection available

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Wet / Chemical

Exposed to moisture, chemicals — stainless, titanium, or PTFE

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3

Budget & Volume

Higher volumes can justify expensive materials. Low volume favors cost-effective options.

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✓

Still Unsure? Talk to Our Engineers

Our material specialists have helped 500+ clients make the right choice. Share your requirements and we'll recommend the optimal material with a detailed cost analysis.

Get Expert Recommendation →
By Industry

Industry-Specific Material Recommendations

Different industries have unique requirements. Here are our most commonly recommended materials by sector.

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Aerospace & Defense

Weight savings and performance are paramount. Strict certification requirements including AS9100.

Ti-6Al-4V Inconel 718 7075 Aluminum 17-4PH PEEK
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Automotive

Balance of cost, performance, and weight. High-volume production with strict tolerance requirements.

6061 Aluminum 4140 Steel 12L14 Steel Nylon 66 ABS
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Medical Devices

Biocompatibility, sterilization compatibility, and regulatory compliance (FDA, ISO 13485) are essential.

316L Stainless Ti-6Al-4V ELI PEEK PTFE PEEK-CA
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Energy & Oil/Gas

Extreme conditions including high pressure, temperature, and corrosive environments.

Inconel 718 Duplex SS 316 Stainless Hastelloy C-276 PTFE
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Consumer Electronics

Aesthetics, thermal management, and lightweight construction drive material selection.

6061 Aluminum Polycarbonate ABS Copper Anodized Al
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Food & Beverage

Hygienic surfaces, corrosion resistance, and FDA compliance for food-contact surfaces.

304 Stainless 316 Stainless PEEK PTFE UHMW-PE
Common Questions

Frequently Asked Questions

Answers to the most common material selection questions we receive from clients. Still have questions? Contact our engineering team.

How do I choose between 304 and 316 stainless steel? +
304 is the standard choice for most applications — it offers excellent corrosion resistance at a lower cost. Choose 316 when your application involves exposure to chlorides (salt water, de-icing salts, certain chemicals) or when higher temperature corrosion resistance is needed. 316 contains molybdenum (2-3%) which significantly improves pitting and crevice corrosion resistance. 316 typically costs 15-25% more than 304.
Is aluminum strong enough to replace steel in my application? +
It depends on the specific requirements. Aluminum alloys like 6061-T6 have about 30% of the strength of structural steel but only 30% of the weight. This means the strength-to-weight ratio can be comparable or even better. For many non-structural-critical applications (brackets, enclosures, housings, fixtures), aluminum is an excellent choice. However, for high-load structural components, steel or titanium may be required. Our engineers can perform a stress analysis to determine the best material for your specific geometry and loading conditions.
What is the most cost-effective material for CNC machining? +
12L14 free-cutting steel is generally the most cost-effective material for CNC machining due to its excellent machinability (fast cutting speeds, long tool life, minimal tool wear). 6061 aluminum is a close second and often the best choice when weight is a factor. For plastics, POM (Delrin) and ABS are the most economical options. The total cost includes both raw material cost and machining time — a cheaper material that machines slowly can end up costing more than a slightly pricier material that machines quickly.
Can I use PEEK as a metal replacement? +
PEEK is one of the best engineering plastics for metal replacement. It offers strength comparable to some aluminum alloys, operates from -260°C to 260°C, has exceptional chemical resistance, and weighs about 1/5th of steel. It's commonly used to replace metals in: wear plates, pump components, seals, bearings, and medical implants. However, PEEK is significantly more expensive than standard plastics (5-10x the cost of ABS) and requires specialized machining techniques. It's typically justified when its unique combination of properties enables weight savings, eliminates corrosion concerns, or allows for design simplification.
How do temperature requirements affect material selection? +
Temperature is one of the most critical factors. Below 150°C, most metals and engineering plastics work well. Between 150-300°C, options narrow to stainless steels, some aluminum alloys, and high-performance plastics like PEEK. Above 300°C, you typically need nickel-based superalloys (Inconel, Hastelloy), titanium, or specialized ceramics. For cryogenic applications (below -50°C), austenitic stainless steels, aluminum, and certain plastics maintain toughness while many carbon steels become brittle. Always specify your full operating temperature range when requesting a quote.
Do you provide material certification documentation? +
Yes. All materials are sourced from certified mills and suppliers. We provide full material traceability including Mill Certificates (MTRs), heat numbers, and chemical/physical property test reports. For aerospace and medical applications, we can also provide RoHS compliance documentation, REACH compliance, and material safety data sheets (MSDS). If your industry requires specific certifications (AMS, ASTM, ISO), please specify them in your request and we'll ensure all documentation is provided with your order.
What surface finishes are available for each material? +
We offer a comprehensive range of surface finishes: Anodizing (Type II & III for aluminum), Passivation (for stainless steel), Zinc/Nickel/Chrome plating (for steel and aluminum), Powder coating (most metals), Bead blasting (all materials), Electropolishing (stainless, titanium), Hard coat anodizing (aluminum for wear resistance), and PVD/DLC coatings (for extreme wear resistance). The choice of finish depends on your functional requirements (corrosion, wear, aesthetics) and the base material compatibility.
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