Custom MIM Parts — From Design to Production

What Are MIM Parts?

MIM parts (Metal Injection Molding parts) are precision metal components manufactured by combining fine metal powder with a thermoplastic binder, injecting the mixture into a mold, then removing the binder and sintering at high temperature until the metal particles fuse into a dense, near-net-shape component. The result is a metal part with the mechanical properties of wrought material but the geometric complexity of injection-molded plastic — at a fraction of the cost of CNC machining for medium-to-high volumes.

MIM parts are used across a wide range of industries — from automotive sensor housings and fuel system components to medical surgical instruments, consumer electronics hinges, firearm fire-control parts, and industrial gear sets. Anywhere a small, complex metal component is needed in quantities of thousands or more, MIM is often the most cost-effective manufacturing route.

Are MIM Parts Strong? Yes — Here's Why

Properly sintered MIM parts achieve 95–99% of theoretical density, meaning they are nearly as dense as wrought or CNC-machined equivalents. Tensile strengths routinely exceed 1,000 MPa for hardened low-alloy steels, and fatigue performance matches wrought material for the same alloy. In firearms applications, MIM hammers and triggers from 17-4PH or 4605 steel sustain thousands of firing cycles without failure. In automotive turbochargers, MIM vanes withstand extreme heat and rotational stress. In medical instruments, MIM surgical jaws pass the same biocompatibility and sterilization tests as machined components.

MIM parts are neither inferior nor inherently weaker — they are engineered components whose quality depends on process control. At Emitech, we monitor density, carbon content, grain structure, and dimensional accuracy on every production batch, so you get consistent mechanical performance lot after lot. For a deeper dive, read our guide on MIM parts strength and MIM parts quality.

MIM Parts vs CNC Machined Parts

CNC machining removes material from a solid billet and is best for prototypes, simple geometries, or very low volumes. MIM parts form near-net-shapes with almost zero material waste — the same complex part that costs $15 to machine might cost $3 with MIM at 10,000 units. However, for ultra-tight tolerances below ±0.02 mm, CNC secondary operations on MIM parts deliver the best of both worlds. Many customers use MIM for the net shape and CNC for critical bores or threads. See our MIM vs CNC machining comparison for a full cost-and-performance breakdown.

How Are MIM Parts Made?

Custom MIM parts follow a four-step manufacturing chain — all under one roof at Emitech:

1. Feedstock compounding — Fine metal powder (5–20 μm) is mixed with thermoplastic binder into a uniform, injectable granulate.
2. Injection molding — The feedstock is heated and injected into a precision mold to form a green part. Wall thickness, gate location, and parting line are optimized during DFM.
3. Debinding & sintering — Binder is removed thermally or with solvent, then the brown part is sintered at 1,200–1,500 °C. Metal particles fuse, and the part shrinks by 15–20% to final dimensions.
4. Post-processing (optional) — CNC secondary ops, heat treatment, passivation, PVD coating, or polishing for enhanced tolerances, strength, or surface finish.

Because MIM is a net-shape process, it can produce undercuts, thin walls, internal threads, and fine surface textures that would be expensive or impractical with CNC machining alone. Material waste is low, repeatability is high, and thousands to millions of identical parts can be manufactured from a single mold set.

At Emitech, we specialize in custom MIM parts for demanding industries — automotive, medical, firearms, aerospace, consumer electronics, and industrial equipment. Our engineering team reviews CAD models, recommends design improvements, builds mold tools, qualifies first articles, and manages ongoing production. This single-source approach gives customers consistent quality, shorter development cycles, and clear communication from prototype to mass production.

Common Types of Custom MIM Parts

Almost any small, complex metal component can be adapted to MIM when the geometry, volume, and material fit the process. Below are the most common categories of custom MIM parts Emitech produces, together with typical applications and design characteristics.

Custom MIM Parts Technical Specifications

Understanding the technical limits of MIM helps engineers specify parts that are both manufacturable and cost-effective. Engineers who design with MIM in mind from the beginning can avoid costly changes later and take full advantage of the process. The table below summarizes Emitech's standard capabilities for custom MIM parts.

Parameter	Specification	Notes
Part weight	0.1 g – 200 g	Ideal range: 0.5 g – 50 g
Maximum dimensions	150 mm × 150 mm × 100 mm	Larger parts may need special review
Wall thickness	0.3 mm – 5 mm	Uniform walls improve sintering quality
As-sintered tolerance	±0.3% – ±0.5%	Refer to our MIM tolerance guide
Post-machining tolerance	±0.02 mm or tighter	For critical fits and bores
Density	95% – 99% of wrought	Depends on material and sintering cycle
Surface finish	Ra 0.8 – 3.2 µm as-sintered	Improved by polishing, plating, or PVD
Tensile strength	Up to 1,000 MPa	Material-dependent
Annual volume	10,000 – 10,000,000+	Mold cavity count matched to volume

Materials for Custom MIM Parts

Material selection directly affects mechanical properties, corrosion resistance, magnetic behavior, and cost. Emitech offers a broad portfolio of MIM materials, from standard stainless steels to specialty alloys for medical, aerospace, and electronic applications. Each material is supplied as a qualified feedstock and processed under controlled parameters to achieve consistent density and mechanical performance.

Material Family	Common Grades	Typical Applications
Stainless steel	316L, 304, 17-4PH, 420, 430L, 440C	Medical instruments, consumer electronics, firearm parts
Low-alloy steel	4605, 8620, 4140, 4340	Gears, shafts, locking components, wear parts
Titanium	Ti-6Al-4V, CP-Ti	Implants, aerospace brackets, premium watch cases
Special alloys	Cobalt chrome F75, Kovar F15, Invar FeNi36	Orthopedic implants, hermetic seals, instrumentation
Soft magnetic	Fe-2Ni, Fe-8Ni, Fe50Co	Solenoid cores, relays, sensors
Copper / tungsten	Copper alloy, tungsten copper	Thermal management, electrical contacts, EDM electrodes

For detailed mechanical data and corrosion performance, visit our MIM materials page. Our metallurgists can also recommend grades based on your strength, hardness, magnetic, or biocompatibility requirements. We can validate material selection through sample production and mechanical testing before mass production begins.

MIM Parts by Material

Emitech manufactures custom MIM parts in more than 50 feedstock formulations. The most commonly requested materials are grouped below by family, with typical applications and achievable mechanical properties.

Not sure which material fits your application? Send us your requirements and our metallurgists will recommend the best alloy based on mechanical, thermal, magnetic, and regulatory requirements.

MIM Parts by Industry

Each industry imposes different performance, certification, and documentation requirements on MIM components. Emitech adapts material selection, process control, and quality deliverables to match the end-use environment.

MOQ and Lead Time for Custom MIM Parts

One of the most common questions from buyers is whether MIM is economical at low volumes. At Emitech, we do not enforce a rigid minimum order quantity. We accept prototype and feasibility runs to validate design, material, and process before mass production. However, the true economic advantage of MIM appears when volumes reach tens of thousands per year, because the upfront tooling cost is spread across many parts.

Stage	Typical Lead Time	Deliverables
DFM review and quote	1–3 business days	Design feedback, material recommendation, tooling plan
Tooling design and build	15–25 days	Precision mold with shrinkage compensation
First article samples	5–10 days after tooling	Sample parts, inspection report, density data
Production lead time	4–6 weeks	Stable sintered parts ready for finishing
Repeat orders	2–4 weeks	Faster turnaround once tooling is qualified

Lead times can vary with part complexity, material availability, and secondary operations such as heat treatment or plating. For urgent projects, we offer expedited sampling and parallel processing of tooling and material procurement. Contact our team for a project-specific schedule.

Industries Served by Emitech MIM Parts

Custom MIM parts are used across a wide range of industries where small size, complex geometry, and high performance are required. Emitech supplies components to automotive suppliers, medical device OEMs, consumer electronics brands, and industrial equipment manufacturers.

• Automotive: Turbocharger vanes, sensor housings, brake components, gearbox selectors, and ADAS hardware. MIM delivers high strength and tight tolerances for safety-critical systems.
• Medical: Surgical jaws, graspers, implantable fixtures, and instrument handles. Biocompatible stainless steels and cobalt chrome meet strict regulatory requirements.
• Consumer electronics: Hinges, frames, connectors, camera brackets, and wearables. MIM enables thin walls and cosmetic surfaces in high-volume products.
• Industrial tools: Gears, locking parts, fasteners, and wear inserts for power tools, robots, and textile machinery. Low-alloy and hardened steels provide durability under mechanical stress.

Why Choose Emitech for Custom MIM Parts?

Emitech supplies precision metal components to global OEMs from our Nanjing facility. Our team combines materials science, mold design, process engineering, and quality management to deliver custom MIM parts that meet demanding specifications.

• Full-process control: We manage feedstock, molding, debinding, sintering, secondary machining, and finishing under one roof.
• Material expertise: More than 50 material grades including stainless steel, titanium, low-alloy steel, soft magnetic alloys, and specialty materials.
• Quality systems: Documented quality management system with CMM inspection, density testing, metallographic analysis, and full traceability.
• Design support: Free DFM review to optimize wall thickness, draft angles, gate location, and shrinkage compensation before tooling.
• Flexible volumes: Prototype, pilot, and mass production with mold cavity counts matched to annual demand.

Whether you need a few thousand parts for a pilot program or millions for a high-volume product, Emitech can scale with you. Our engineers work directly with your team to reduce risk, shorten development time, and ensure repeatable quality.

Custom MIM Part Design Guidelines

Good design practices reduce tooling cost, improve yield, and shorten the path from first article to stable production. The following guidelines help engineers create MIM-friendly parts from the start. For a complete engineering reference, see our MIM design guide.

• Wall thickness: Keep walls between 0.3 mm and 5 mm. Sudden changes in thickness cause differential shrinkage, warpage, and cracks during sintering. Transition gradually and use ribs or gussets for stiffness instead of thick sections.
• Radii and corners: Avoid sharp internal corners. A minimum radius of 0.2 mm reduces stress concentration and improves feedstock flow. External radii also help ejection and lower mold wear.
• Draft angles: Provide 0.5° to 2° of draft on vertical walls to assist part ejection. Zero-draft features are possible in some cases but may increase tool complexity and cost.
• Parting line: Design the parting line on a flat plane whenever possible. Complex parting lines add tooling cost and can create flash that requires secondary cleaning.
• Undercuts and cores: MIM can mold internal threads, holes, and undercuts using side cores or collapsible cores. However, each core action adds tooling cost and cycle time, so keep core geometry as simple as the function allows.

Our engineers review every incoming design for manufacturability and provide a report with suggested changes before any metal is cut. This DFM step typically saves weeks of rework and avoids surprises during first article inspection.

Frequently Asked Questions

Get a Quote for Your Custom MIM Parts

Whether you need prototype samples, a pilot run, or high-volume production, Emitech can deliver custom MIM parts that meet your mechanical, cosmetic, and regulatory requirements. Upload your drawing or 3D model and receive a detailed quotation with DFM feedback within 48 hours.