Material Selection FAQ

Selecting the right manufacturing material depends on your specific development phase.

• Visual Models (Look-Like Prototypes): If you need to verify aesthetics, fit, and finish, choose ABS or Acrylic (PMMA). These materials are cost-effective, easy to polish, and paintable for cosmetic presentations.

• Functional Testing (Work-Like Prototypes): For verifying mechanical properties like snap-fits or friction, specify Nylon (PA6/PA66) or POM (Delrin). These engineering plastics offer excellent durability and wear resistance.

• Structural Verification: For load-bearing parts, choose Aluminum 6061-T6 or Stainless Steel 304. They provide the necessary tensile strength and structural integrity.

• High-Stress & End-Use: For extreme environments requiring heat resistance or chemical stability, upgrade to high-performance materials like Titanium Ti-6Al-4V, PEEK, Ultem (PEI), or Aluminum 7075.

Yes, material authenticity is critical for manufacturing quality. For all CNC machining and injection molding orders, Boona Prototypes provides full traceability documentation upon request:

• Material Mill Certificates (Heat Numbers): We trace the raw metal back to the foundry to prove the chemical composition matches international standards (e.g., ASTM B209 for Aluminum, ASTM A276 for Steel).

• Certificate of Conformity (CoC): A formal declaration guaranteeing that the manufactured parts meet your drawing specifications and industry tolerances.

Yes. We are committed to global environmental compliance standards.

• RoHS Compliant: Most of our metals (Aluminum, Stainless Steel) and plastics (ABS, Polycarbonate, Nylon) are free from hazardous substances like Lead (Pb), Mercury (Hg), and Cadmium (Cd), making them safe for electronics exported to the EU market.

• REACH Regulation: We monitor our supply chain to ensure compliance with EU chemical safety regulations. If you need compliance documentation for specific alloys like Brass C3600, please specify this in your quote request.

• Aluminum 6061-T6 (The Standard): This is the most versatile CNC machining alloy. It offers an excellent balance of strength, corrosion resistance, weldability, and low manufacturing cost. It is the standard choice for electronic enclosures, brackets, drone frames, and consumer electronics.

• Aluminum 7075-T6 (Aerospace Grade): Choose this only if high strength-to-weight ratio is critical. It is nearly 2x stronger than 6061 (comparable to mild steel) and has high fatigue strength. It is the preferred material for aerospace components, high-stress gears, rock climbing equipment, and bicycle shafts.

• Stainless Steel 304 (SS304): The most common commercial grade stainless steel. It offers good corrosion resistance for indoor applications and general manufacturing.

• Stainless Steel 316 (Marine Grade SS316): Contains Molybdenum, which gives it superior resistance to saltwater (chlorides) and industrial acids. It is mandatory for medical devices (surgical instruments), food processing machinery, marine hardware, and chemical processing equipment.

• Magnesium (AZ31B / AZ91D): The lightest structural metal available (33% lighter than Aluminum). It offers excellent vibration damping and electromagnetic shielding. Ideal for handheld devices, cameras, and lightweight drone bodies where every gram counts.

• Titanium (Ti-6Al-4V Grade 5): Heavier than Magnesium but significantly stronger and has the highest strength-to-weight ratio of any metal. It is biocompatible (non-toxic to the human body) and corrosion-immune, making it the #1 choice for medical implants and high-heat aerospace engine parts.

• Copper (C1100 / C101): Pure Oxygen-Free Copper offers the highest electrical and thermal conductivity (99.9% Pure). Use it for heat sinks, bus bars, electrodes, and power transmission components. Note that Copper is gummy and harder to machine than Brass.

• Brass (C3600 / C260): Lower conductivity than copper but much harder, stronger, and has excellent machinability (free-machining). Ideal for threaded fittings, valves, decorative hardware, bearings, and sensor housings.

• Acrylic (PMMA): The clearest plastic available. It can be vapor polished to a glass-like optical finish. However, it is brittle and can crack under stress. Best for display screens, light guides, and decorative panels.

• Polycarbonate (PC): Transparent but extremely tough and impact-resistant (bulletproof glass material). It has higher heat resistance than Acrylic. Choose PC for rugged clear cases, safety lenses, and light pipes that must withstand impact and rough handling.

• POM (Acetal / Delrin): The “Low Friction” king. It is a self-lubricating thermoplastic with high stiffness and low moisture absorption. Perfect for precision gears, bearings, bushings, and sliding mechanisms that need to hold tight tolerances.

• PEEK (Polyetheretherketone): The “Super Plastic.” It is a high-performance thermoplastic that withstands 260°C continuous heat, aggressive chemicals, and repeated sterilization (autoclave). Used to replace metal components in aerospace, automotive, and medical implant applications.

• HDPE (High-Density Polyethylene): Excellent chemical resistance to solvents and acids, with high impact strength. It is a low-cost, FDA-compliant material standard for fluid containers, cutting boards, and piping.

• Polypropylene (PP): Highly resistant to acids and organic solvents. Known for its unique “Living Hinge” capability (can bend repeatedly without fatigue failure). Ideal for packaging, chemical tanks, and snap-top lids.

• PET (Polyethylene Terephthalate): FDA compliant, low moisture absorption, and dimensionally stable. Ideal for food processing machinery parts and beverage containers.

• SLA Resin (Stereolithography): Produces a smooth, high-resolution surface finish comparable to injection molding. Best for visual verification, master patterns for vacuum casting, and concept models. Warning: Standard resins can be brittle and UV sensitive.

• SLS Nylon (PA12 Powder Sintering): Produces a strong, functional part with a slightly grainy texture. It is isotropic (equally strong in all directions) and requires no support structures. Best for functional testing, snap-fits, living hinges, and low-volume end-use production.

• Vacuum Casting (PU Rubber): The best option for functional rubber prototypes. We use Polyurethane resins (like Hei-Cast) that simulate TPE/TPU properties with specific hardness (Shore A 30 to 90).

• Flexible 3D Printing (DLP/PolyJet): Good for visual “look and feel” models but generally lacks the tear strength of production rubber.

Many clients ask this. Here is the breakdown:

• Aluminum 6061-T6: The industry “workhorse.” It has excellent corrosion resistance, is weldable, and is lower cost. Choose this for standard enclosures, brackets, and electronic housings.

• Aluminum 7075-T6: The “aircraft grade.” It is nearly as strong as steel but ultra-light. However, it is not weldable and costs ~50% more. Choose this for high-stress structural parts or aerospace components.

• SS 303: Designed for easy machining (contains sulfur). Ideal for complex nuts, bolts, and fittings. Not for welding.

• SS 304: The standard for general industry. Good corrosion resistance and weldability. Used for kitchenware and industrial housing.

• SS 316: Medical & Marine grade. Contains Molybdenum for superior resistance to salt water and chlorides. Essential for Medical Devices and Outdoor Marine equipment.

• SPCC (Cold Rolled Steel): Strong and cheap, but it will rust if not painted or plated immediately.

• SECC (Electro-Galvanized Steel): Pre-coated with zinc. It offers rust protection while maintaining electrical conductivity. Ideal for EMI Shielding chassis in electronics. Learn more at our Sheet Metal Fabrication page.

• Grade 2 (Pure): Excellent corrosion resistance (best for chemical processing) but lower strength.

• Grade 5 (Ti-6Al-4V): High strength and heat resistance. This is the standard for Aerospace and Medical Implants. Boona machines both grades with precision.

• Copper (C1100/C101): Highest thermal and electrical conductivity. Used for heat sinks and busbars. Harder to machine (gummy).

• Brass (C360): Excellent machinability (cuts very fast). Ideal for low-friction gears, valves, and decorative fittings.

PC is tougher. Polycarbonate is virtually unbreakable and used for bulletproof glass. ABS is rigid and cheaper but can crack under heavy impact.

• Tip: If you need a clear part, choose PC (can be vapor polished). If you need to paint/glue the part, ABS is easier to process.

Choose POM if you need high dimensional stability and low friction (e.g., gears, sliding bushings). Nylon is stronger but absorbs moisture (hygroscopic), which can cause parts to swell or lose tolerance in humid environments.

PEEK is a super-engineering plastic. It withstands 250°C+, resists aggressive chemicals, and is biocompatible.

• Cost: It is expensive (10x-20x price of ABS).

• Verdict: Only use PEEK for critical applications like Aerospace valves, Medical Implants, or Oil & Gas downhole parts where failure is not an option.

Polypropylene (PP). It has incredible fatigue resistance and can be bent thousands of times without breaking. For prototypes, we machine PP or use specialized Vacuum Casting resins that simulate PP properties.

Yes. Adding glass fiber significantly increases stiffness and strength. However, be aware that glass fibers make the material abrasive (increases tool wear) and the surface finish will be matte/grainy, not glossy.

For food processing equipment, we recommend:

• Metals: Stainless Steel 316L (best) or 304.

• Plastics: Natural PEEK, HDPE, or specific grades of PET/POM.

• Important: Please specify “Food Safe” in your quote so we use approved coolants during machining.

• Surgical Tools: Stainless Steel 17-4PH (Hardenable) or 316L.

• Implants: Titanium Grade 5 (Ti-6Al-4V) or Medical PEEK.

• Housings: Medical-grade PSU (Polysulfone) or PC. We can provide material certifications (CoC) for traceability.

Yes. Static can destroy sensitive electronics during assembly. We offer ESD-Acetal (Delrin) and ESD-Ultem for manufacturing PCB jigs, fixtures, and pallets.

 Yes. The vast majority of our CNC and injection molding materials comply with EU RoHS and REACH standards. If you need specific lab reports, please inform our team.

Not exactly.

• Injection Molding: Uses real thermoplastic pellets (e.g., real ABS).

• 3D Printing (SLA/FDM): Uses simulants (e.g., “ABS-like Resin”).

• Impact: 3D printed “ABS-like” parts are more brittle and have lower heat resistance than molded ABS. For functional verification, consider CNC Machining the real material.

If you need strength without mold costs, we recommend:

• CNC Machining: In real ABS, Nylon, or Aluminum.

• 3D Printing: SLS Nylon (PA12). It is durable, heat-resistant, and requires no support structures.

When ordering soft parts via Vacuum Casting or Injection Molding, you must specify Shore A hardness:

• Shore 30A: Soft (Rubber band).

• Shore 70A: Medium (Car tire / Shoe sole).

• Shore 90A: Hard (Shopping cart wheel).

Yes.

• Magnesium (AZ31B): Lighter than aluminum, excellent vibration damping. (Requires safety protocols due to flammability).

• Inconel (718/625): Extreme heat resistance for turbochargers/jet engines. Hard to machine, but we have the capability.

Materials come in standard blocks or sheets (e.g., 5mm, 10mm, 20mm thick).

• Cost Tip: If your part is designed as 22mm thick, we must buy a 30mm block and machine away 8mm. Changing your design to 19mm allows us to use a 20mm block, saving significant material cost and time.

Yes. Upon request, we provide the original mill certificate showing the chemical composition and heat number of the raw material. This is standard for our Quality Control process.

If we set Aluminum 6061 as the baseline (Index 1.0), here is a rough relative cost guide for raw material:

• Carbon Steel (Low Carbon): ~0.5x (Cheapest)

• Aluminum 6061: 1.0x (Standard)

• Stainless Steel 304: ~2.0x

• Stainless Steel 316: ~2.5x

• Aluminum 7075: ~3.0x

• Titanium Gr5: ~10.0x + (High machining cost)

• Tip: Raw material is only part of the cost. Steel takes longer to machine than Aluminum, so the final part price might be similar.

Generally, No. Die-cast aluminum contains high silicon content, which results in a dark, blotchy, and ugly anodized finish.

• Alternative: For die-cast parts, we recommend Powder Coating or E-Coating for a smooth, protective finish. If you need a beautiful anodized look, you must use CNC Machining with 6061/5052 aluminum.

Stainless steel threads (bolt and nut) can “seize” or lock up together under friction (Cold Welding).

• Solution: Use different grades for the bolt and nut (e.g., SS 316 bolt with SS 304 nut) or apply anti-seize lubricant.

Be careful when assembling plastic parts with metal screws. Plastics expand with heat 10x more than metals.

• Risk: If the fit is too tight, the plastic part may crack when the temperature rises.

• Design: Allow clearance holes or use slots to accommodate thermal expansion.

• 65Mn (Spring Steel): Extremely strong and resilient. Used for clips and springs. Must be plated (Zinc/Nickel) or it will rust instantly.

• SS 301 (Spring Temper): Corrosion resistant by nature. Best for medical clips or outdoor springs where plating is risky or impossible.

Yes, but it is specialized.

• Macor: A machinable glass-ceramic. Excellent electrical insulator and withstands very high heat. Machined with standard carbide tools.

• Alumina (Al2O3): Extremely hard. Requires diamond grinding. Used for high-wear nozzles and insulators.

Yes. We machine Isostatic Graphite to create electrodes for EDM (Electrical Discharge Machining). Graphite is messy to machine but conducts electricity perfectly to burn shapes into hardened steel molds.

• Plates: We CNC cut flat patterns from pre-made Carbon Fiber sheets (great for drone frames).

• Tubes/Shapes: We can source roll-wrapped tubes.

• Note: We generally do not offer “lay-up” molding for complex curved carbon fiber geometries (like bike frames) in low volume.

These materials have added elements (Lead, Sulfur, etc.) to make chips break easily, allowing for super-fast machining.

• Steel: 12L14 (Lead alloy).

• Brass: C360.

• Warning: These are Not RoHS compliant (due to Lead) and not weldable. Do not use for export to EU if RoHS is required.

• Rockwell C (HRC): Used for hard metals (Heat-treated Steel, Ti). E.g., a knife blade is HRC 58-60.

• Brinell (HB): Used for softer metals (Aluminum, Cast Iron).

• Shore (A/D): Used for Plastics and Rubbers.

• Why it matters: Specifying the correct hardness ensures your part won’t wear out or indent.