Materials

The material decides
more than the drawing does.

At micro scale a resin's shrink spread can take most of a tolerance before the process has done anything, and a metal's stiffness decides the last micron of a thin wall. These are the materials this shop runs, compared on the behavior that matters for a small part.

12 materials shown

These are standards the material grade is tested or supplied to by its manufacturer. They describe the resin or the bar stock, not a finished part — qualifying a part for patient contact is the device owner's decision, made under their own quality system.

Molded resins

PEEK

High-temp · biocompatible

Polyether ether ketone is the gold-standard structural thermoplastic for implantable and sterilizable devices. It retains strength at continuous-use temperatures above 250 °C and resists aggressive chemical sterilants.

Typical grades
Victrex 450G, 150CA30
Thermal
Tg 143 °C · Tm 343 °C

Key properties

  • Continuous-use temp to 260 °C
  • Tensile strength 100 MPa unfilled
  • Chemical resistance to most sterilants
  • Radiolucent — MRI/X-ray transparent
  • Low moisture absorption < 0.5%

Certifications

  • ISO 10993 biocompatibility
  • USP Class VI
  • ASTM F2026 implant grade

Processes Micro injection molding

Choose it for
Heat, sterilization and chemical resistance in a structural part.
What it punishes
Mold temperature sets crystallinity and shrink; filled grades shrink differently across the flow.

PEEK in depth

LCP

Thin-wall · micro-flow

Liquid Crystal Polymer offers the lowest melt viscosity of any structural thermoplastic, enabling sub-0.1 mm wall sections in micro injection molding. Dimensional stability after molding is exceptional — linear shrink is near zero in the flow direction.

Typical grades
Vectra E130i, Sumikasuper E6000
Thermal
HDT 240 °C

Key properties

  • Wall sections to < 0.08 mm achievable
  • Near-zero anisotropic shrinkage
  • Low CTE < 5 ppm/°C (filled grades)
  • Low outgassing — suitable for vacuum use
  • Inherent flame retardance UL94 V-0

Certifications

  • UL94 V-0
  • RoHS compliant

Processes Micro injection molding

Choose it for
Walls thinner than other resins will fill.
What it punishes
Weak weld lines, and near-zero shrink along the flow but not across it.

LCP and COC in depth

COC

Optical · low extractables

Cyclic olefin copolymer combines glass-like optical clarity with extremely low extractables and leachables, making it the preferred substrate for microfluidic diagnostics, drug-delivery cartridges, and lab-on-chip devices.

Typical grades
Topas 5013, 6013
Thermal
Tg 135 °C

Key properties

  • Transmission > 92% across visible spectrum
  • Extremely low extractables and leachables
  • Near-zero birefringence for optical polarimetry
  • Water absorption < 0.01%
  • Compatible with UV bonding and laser welding

Certifications

  • USP Class VI
  • ISO 10993-5
  • FDA Drug Master File support

Processes Micro injection molding

Choose it for
Clear, dry, low-extractable parts: microfluidics, diagnostics, optics.
What it punishes
Flow lines and stress show as birefringence; the cavity finish is the part finish.

LCP and COC in depth

Ultem (PEI)

Flame-rated · autoclavable

Polyetherimide offers a rare combination of continuous-use temperature, inherent flame retardance without additives, and autoclave compatibility — making it the standard choice for reusable surgical instrument handles and housings.

Typical grades
1010, 2300
Thermal
HDT 200 °C

Key properties

  • Continuous-use temp to 170 °C
  • Inherent UL94 V-0 without flame-retardant additives
  • 1000+ autoclave cycles demonstrated
  • Tensile strength 105 MPa
  • Transparent in natural grade

Certifications

  • UL94 V-0
  • USP Class VI
  • ISO 10993 compliant grades

Processes Micro injection molding

Choose it for
Dimensional stability, flame rating and repeated autoclaving.
What it punishes
Notch sensitivity and molded-in stress — the corners, not the tolerances.

Ultem in depth

PC

Transparent · impact-resistant

Polycarbonate is the workhorse optical and structural thermoplastic for device housings, windows, and transparent enclosures. Its toughness and transparency make it the go-to for surgical enclosures and diagnostic cartridge bodies.

Typical grades
Makrolon Rx2440
Thermal
HDT 135 °C

Key properties

  • Highest impact strength among commodity plastics
  • Optical transmission > 88%
  • Service temp to 120 °C
  • Excellent dimensional stability
  • Wide colour and opacity range

Certifications

  • USP Class VI grades available
  • ISO 10993 compliant grades

Processes Micro injection molding

ABS

General-purpose · prototype

ABS provides excellent processability and surface finish for non-implantable device components, housings, and prototype runs.

Key properties

  • Easy processing, wide molding window
  • Good surface finish, paintable
  • Service temp to 80 °C
  • Broad colour palette available

Certifications

  • UL94 HB standard; V-0 grades available

Processes Micro injection molding

PPSU

Steam-sterilizable · FDA-listed

Polyphenylsulfone provides superior steam and chemical sterilization resistance among polysulfone-family resins, supporting aggressive hospital reprocessing protocols. Its amber/transparent appearance is recognizable in reusable surgical tray components.

Typical grades
Radel R-5500
Thermal
HDT 207 °C

Key properties

  • Withstands 1000+ steam sterilization cycles
  • Resistant to aggressive hospital disinfectants
  • Service temp to 180 °C (short-term)
  • Inherent hydrolysis resistance
  • Translucent amber in natural colour

Certifications

  • FDA food-contact listed
  • USP Class VI
  • ISO 10993 compliant

Processes Micro injection molding

Machined metals

316L SS

Corrosion-resistant · implant grade

316L stainless steel is the most widely used metal in medical device manufacturing. Low carbon content minimizes sensitization, and its corrosion resistance in chloride-containing body fluids makes it the default for instruments and implants.

Key properties

  • Tensile strength 485 MPa (annealed)
  • Excellent corrosion resistance in body fluids
  • Non-magnetic in annealed condition
  • Good machinability for milling and grinding
  • Low carbon content < 0.03% prevents sensitization

Certifications

  • ASTM F138 implant grade
  • ISO 5832-1
  • ASTM A276

Processes 5-axis micro milling · Insert molding

Choose it for
Corrosion resistance (316L) or strength (17-4 PH).
What it punishes
Work-hardens under a light cut; burrs rather than breaks.

Stainless steel in depth

17-4 PH SS

Precipitation-hardened · high-strength

17-4 PH is a precipitation-hardening stainless steel offering 2× the yield strength of 316L after H900 aging. It is used for surgical cutting tools, springs, and structural implant components where higher mechanical loads require a stainless alloy.

Key properties

  • Yield strength to 1170 MPa (H900 condition)
  • Hardness to 44 HRC
  • Good corrosion resistance (less than 316L)
  • Magnetic after aging
  • Excellent surface finish capability

Certifications

  • ASTM A564
  • AMS 5643
  • ISO 5832-9 equivalent

Processes 5-axis micro milling · Surface grinding

Stainless steel in depth

Ti-6Al-4V

Biocompatible · lightweight

Ti-6Al-4V (Grade 5/23) is the most commonly implanted structural metal alloy. Its combination of specific strength, osseointegration capability, and MRI compatibility makes it the default for orthopedic and spinal implants.

Key properties

  • Density 4.43 g/cm³ — 43% lighter than steel
  • Tensile strength 950 MPa (Grade 5)
  • Osseointegration capability for bone contact
  • MRI conditional — low magnetic susceptibility
  • Excellent fatigue resistance

Certifications

  • ASTM F136 implant grade (ELI)
  • ISO 5832-3
  • AMS 4928

Processes 5-axis micro milling

Choose it for
Strength per gram; implants and instruments.
What it punishes
Heat stays at the edge, and low stiffness springs thin walls back.

Titanium in depth

W-Carbide

Wear tooling · hard-millable

Cemented tungsten carbide is used where extreme wear resistance and stiffness are required — cutting edges on surgical reamers, mold cores for abrasive plastics, and precision gauge components. Hard-milling on the GRA100 and surface grinding are the primary in-house removal processes.

Key properties

  • Hardness 1400–1800 HV (grade-dependent)
  • Young's modulus 550–700 GPa (3× steel)
  • Compressive strength > 4000 MPa
  • Low CTE 5–7 ppm/°C
  • Hard milling and surface grinding as primary machining methods

Certifications

  • ASTM B406
  • ISO 513 classification

Processes 5-axis micro milling · Surface grinding

Inconel 625/718

High-temp · corrosion-resistant

Inconel nickel superalloys maintain strength at temperatures that soften stainless and titanium. They are specified for aerospace fuel system components, high-temperature sensors, and surgical tools used in electrosurgery or laser environments.

Key properties

  • Service temp to 980 °C (625) / 700 °C (718)
  • Outstanding oxidation and hot-corrosion resistance
  • Tensile strength 830 MPa (625 annealed)
  • Non-magnetic
  • Challenging to machine — rapid tool wear

Certifications

  • AMS 5666 (625)
  • AMS 5662 (718)
  • ASTM B443 / B637

Processes 5-axis micro milling

Choosing between them

Does the part need to survive heat, sterilization or chemicals?

PEEK for the most demanding, Ultem and PPSU where amorphous stability matters more than ultimate chemical resistance.

Are the walls thinner than the resin wants to fill?

LCP. Nothing else flows as far into as thin a section — at the cost of weak weld lines.

Does it need to be clear, or carry a fluid?

COC for optics and fluid paths, PC where clarity matters and chemistry is gentler.

Does a dimension need to hold across the flow?

An amorphous, unfilled resin. Filled grades and LCP shrink differently across the flow than along it.

Does it need to be metal?

Titanium for strength per gram, 316L for corrosion resistance, 17-4 PH for strength in stainless.

Have a part in one of these materials?

Send the drawing with the grade and the dimensions that matter.

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How much of a tolerance each resin's shrink takes on its own is in the shrinkage calculator.