Medical Device Prototype Parts: Enclosures, Housings and Instrument Components

Medical device teams prototype under a constraint that other industries do not have: the part has to be built early enough to inform the design, but the material, finish and documentation trail have to survive scrutiny later. SkillsProto builds prototype enclosures, instrument housings, test fixtures and assembly jigs for that stage — CNC machining at ±0.005 mm on critical features, MOQ 1, 3-7 working days, plus injection molding, 3D printing, sheet metal and vacuum casting from the same plant in Shenzhen. We build prototypes, fixtures and low-volume parts; we do not manufacture implanted or sterile finished devices, and we make no claim to hold ISO 13485.

What we build for medical programmes

Material choice: specify it, do not leave it open

Material decisions in medical work are documented decisions, so we do not substitute them. Tell us the grade and we will source it; if a grade is not stocked in Shenzhen we will say so before quoting rather than proposing an equivalent. The materials that come up most often:

• 304 and 316 stainless — instrument bodies, handles, reusable trays, anything that sees autoclave or aggressive cleaning.

• 6061 and 7075 aluminium — fixture plates, jig bodies, structural housings where weight matters and sterilisation is not the driver.

• PEEK — high temperature, chemically resistant, radiolucent; machined rather than printed where dimensional stability matters.

• POM (Delrin) — low friction, dimensionally stable, common for mechanism parts and fluid manifolds.

• PC and ABS — enclosures and covers; PC where impact resistance or a clear window is wanted, ABS where cost and paintability matter.

• Silicone-like and PU vacuum cast resins — soft-touch overmould simulation, gaskets and seals in 10-500 piece runs.

We do not hold or claim biological evaluation. If your part needs ISO 10993 cytotoxicity or biocompatibility evidence, that testing belongs to the material supplier and your own verification process; we supply the part, the material certificate where the mill provides one, and the dimensional report.

Surface finish and cleanability

Finish is functional in this sector, not cosmetic. A bead-blasted aluminium enclosure hides handling marks but holds residue in the texture; a brushed or electropolished surface cleans more predictably. Internal corners need a radius a cleaning swab can reach — sharp internal corners are a design problem, not a finishing problem. For enclosures that must seal, flatness on the gasket face matters more than the ±0.05 mm general tolerance, so call flatness explicitly and we will machine and measure to it.

Documentation that comes with the part

Every order ships with a first article inspection report. Where the drawing calls out specific features, CMM measurement data can be requested for those features. Material certificates are provided when the mill or resin supplier issues one and you ask for it at quote stage — not retrofitted afterwards. If your quality system needs a specific document format, send the template with the RFQ and we will confirm whether we can fill it before accepting the order.

How evaluation batches usually run

A typical path looks like this. One or two printed or machined enclosures confirm the PCB and connector stack, then a machined version in the intended material goes to user handling, then a batch of 10-200 by vacuum casting or aluminium tooling supports clinical evaluation with production-like texture, colour and feel. Each step costs more than the last and tells you something the previous step could not, so the useful question is not which process is cheapest but which one answers the question you currently have. Teams that skip the machined step often discover a wall thickness or button travel problem only after the evaluation batch is built, which is the expensive place to find it.

What we do not do

Being explicit here saves a week on both sides. SkillsProto does not manufacture implantable devices, sterile packaged finished devices, or parts intended to be placed on the market as regulated finished medical devices. We do not hold ISO 13485 and make no certification claim. We do not perform biological evaluation, sterilisation validation or packaging validation. If your programme needs a certified contract manufacturer for regulated production, engage one — and use us for the fixtures, prototypes and pre-production builds that get you there.