Services
Micro Part Design
Before your design is set in steel, let's optimize your DFM.
MTD's team—molding, tooling, and metrology—helps you determine what's possible, cost-effective, and scalable.
When do I need micro molding?
The common assumption is that "micro molding" means small parts — sub-gram shots, components that practically disappear on your fingertip.
MTD does manufacture some of the smallest medical devices in the world.
But larger components can also require micro molding's specialized tools and techniques to create complex geometries and features.
You need micro molding when your design demands any of the following:
- Ultra-thin walls: Walls measured in thousandths of an inch, on flow lengths that conventional presses cannot fill.
- Complex geometries: Geometries that fight conventional fill, pack, knit-line behavior, and ejection.
- Tight tolerances: Tolerances that exceed the resolution of conventional press control, conventional tooling, and standard inspection methods.
- Micro-scale features: Tiny holes, small radii, sharp edges, or small critical dimensions anywhere on the part — regardless of how large the surrounding part is.
Examples of Micro Features
.004"
(.102mm)
Walls
R.001"
(.025mm)
Edges/Corners
Ø0.004”
(0.102mm)
Holes
R.0002"
(5μ)
Sharp Tip
Examples from MTD's production floor:
- Drug delivery device with a 0.005" long-distance wall
- 0.950" long device with a 0.030" ID and 0.004" minimum wall
- 1.3" long part with 0.5 mm holes and zero draft
- 0.6" flow tube with a 0.0046" ID and 0.033" hole
- Multi-foot-long wire with a complex overmolded component
What a design engagement delivers
A formal DFM review at MTD produces:
- Feature-risk mapping against the selected material and tolerance
- Gate and runner strategy, with parting-line options
- Ejection strategy tailored to the geometry
- Material-to-geometry compatibility notes, including alternatives where the spec'd resin will not hold
- A summary of recommended design changes, tool-cost implications, and program-risk read — before steel is committed
A useful test when selecting a molding partner: silence is not always confidence. The best manufacturing partnerships are built on early questions — about part function, risk areas, tolerances, and manufacturability. Those conversations often uncover opportunities that improve performance and reduce downstream issues.
The strongest programs happen when the customer brings the design intent and the limits of success and failure for each feature, and the molder brings the manufacturing reality.
It is never too early — or too late — to bring MTD into the design process. Early collaboration often creates more options, fewer surprises, and a smoother path to launch.
Micro Technology Tools
MTD can use in-house technologies to optimize your micro part design.
MicroFill
Determine the material’s sheer sensitivity by using a spiral mold at selected melt temperature.
MicroFlow
Determine realistic wall thicknesses for certain materials by running multiple injection velocities while measuring flow length at various thicknesses.
MicroRunner
Determine the minimum runner size required to produce your component without sacrificing quality or wasting material.
Part design decisions don't live in isolation — they cascade into tool complexity, processing windows, and measurement strategy.
The earlier we see the design, the more room we have to collaborate on every downstream tradeoff.
How can we ensure our device meets tight tolerances required for its application?
The best results come from aligning part design, material selection, tooling strategy, molding process, and inspection methods from the beginning. In micromolding, repeatability is critical, so we focus on designing features that can not only be molded consistently, but also measured and validated with confidence.
What can be the risks of part design when transitioning to large-scale production?
Features that perform well in early prototypes do not always translate easily into validated production. Common challenges include material variation, tolerance stack-up, difficult-to-measure features, and process windows that become too narrow at higher volumes. Early DFM and process development help identify those risks before tooling is finalized.
How can we further reduce the size of our device without compromising performance?
Successful miniaturization requires balancing feature size, material behavior, manufacturability, and functional performance together. In many cases, we can work with the customer to reduce overall footprint by integrating features directly into the molded component, consolidating parts, or optimizing geometry while maintaining structural and functional integrity.
What's the difference between single-shot micro injection molding and overmolding?
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Can MTD evaluate multiple design iterations before we commit to production tooling?
Yes. We regularly work through multiple design iterations during development to evaluate manufacturability, feature performance, tolerance feasibility, and inspection strategy before production tooling is released. That process helps reduce downstream changes, delays, and validation risk.
What strategies can reduce costs, optimize cavitation, minimize material waste, and improve overall efficiency without compromising part performance?
Cost reduction is usually most effective when it is addressed early in the design phase. Simplifying geometry, reducing secondary operations, optimizing gate and runner design, selecting the right cavitation strategy, and designing for stable processing can significantly improve efficiency while maintaining part performance and consistency.
What feature sizes and tolerances can MTD design for in production?
MTD regularly supports production programs with wall stock in the 0.002–0.004 inch range, hole diameters near 0.002 inches, and radii as small as 0.0002 inches / 5 µm. Production tolerances are commonly held in the 0.001–0.002 inch range, depending on the material, geometry, tooling approach, and inspection requirements.
How do I know if my part actually needs micromolding, or whether conventional injection molding would work?
Micromolding is typically the right solution when part performance depends on extremely small features, thin walls, tight tolerances, delicate inserts, or very small shot sizes that conventional molding processes struggle to control consistently. The critical factor is often the size and precision of the features—not simply the overall size of the part.
How early should we engage a micro injection molder in our product development process?
The earlier, the better. Early collaboration during concept and development stages allows design, material selection, tooling strategy, manufacturability, and inspection requirements to be aligned before costly changes become necessary later in the program.
What design decisions most often reduce unit cost without compromising function?
Some of the most effective cost-saving decisions include simplifying geometry, avoiding unnecessary tight tolerances, maintaining consistent wall stock, reducing secondary assembly steps, and designing features that can be molded and inspected repeatedly. Well-designed parts are typically easier to process consistently at scale, which improves both efficiency and overall cost performance.
100% MICRO • 100% MEDICAL & HEALTHTECH • 100% IN-HOUSE
Micro Materials
Micro Part Design
Micro Tooling
Micro Molding
Micro Metrology
