Custom MIM Parts — OEM Components Made to Your Specification
Quick Answer
Emitech manufactures custom MIM parts to customer specifications across a wide range of materials, geometries, and volume requirements. Whether you need a single prototype for design validation or 200,000 production parts per year, our metal injection molding process delivers net-shape complexity, consistent material properties, and repeatable tolerances. Send your drawing for a free DFM review within one business day.
Custom MIM parts combine the design freedom of plastic injection molding with the strength and performance of engineered metals. At Emitech, we work with OEM buyers to develop components that match exact mechanical, dimensional, and cosmetic requirements—without the material waste and long cycle times of conventional machining. From prototype tooling to multi-cavity production molds, our team manages every step from feedstock selection through sintering, secondary machining, surface treatment, and final inspection.
What We Customize
- Geometry: Complex 3D contours, undercuts, internal channels, thin walls to 0.3 mm, multi-diameter features, and parting-line-free cosmetic surfaces. If it can be injection molded in plastic, it can likely be MIM'd in metal.
- Material: Choose from our MIM material catalog—stainless steels (316L, 304, 17-4PH, 420, 440C), low-alloy steels (4605, 4140, 8620), tool steels, titanium, copper alloys, and Kovar. Custom powder blends available for specialty applications.
- Surface Finish: As-sintered Ra 0.8–1.6 μm, with post-processing options including passivation, electropolishing, PVD coating, electroless nickel plating, black oxide, and bead blasting.
- Tolerances: Standard ±0.3% of nominal. Critical features held to ±0.05 mm or tighter via in-house CNC secondary operations. See our MIM tolerance guide for capability data.
- Volume: Prototype runs from 100 pieces. Production volumes from 5,000 to 2,000,000+ pieces per year. Multi-cavity tooling (2–8 cavities) for high-volume programs.
Custom MIM Parts Case Study
Case Study: Custom 4140 Low-Alloy Steel Locking Pawl
Challenge: A safety equipment manufacturer needed a custom locking pawl for a fall-arrest device. The part required 4140 low-alloy steel for strength, a complex pawl tooth profile with a 60° included angle, a pivot bore with ±0.025 mm tolerance, and carburizing to 55–60 HRC on the tooth surface. Production volume was 60,000 units per year.
Solution: Emitech designed a single-cavity MIM mold with the pawl oriented so that the tooth profile was formed in the cavity with no weld lines. The pivot bore was produced slightly undersize in MIM and then finish-honed to ±0.025 mm. After sintering, the pawl teeth were masked and the part was gas-carburized to the specified case depth and hardness.
Results: The MIM pawl passed the customer's 50,000-cycle endurance test without tooth deformation. Per-part cost at 60,000 units was 48% lower than the previously machined-from-blank approach. The customer subsequently redesigned three additional safety device components for MIM production based on this success.
Frequently Asked Questions
Q: What is the difference between custom MIM parts and stock MIM parts?
Custom MIM parts are manufactured to your unique design and specifications. Unlike stock or catalog parts, custom MIM parts require tooling development, process validation, and first-article approval before production. The result is a part that fits your exact application without compromise.
Q: What is the minimum order quantity for custom MIM parts?
Standard production MOQ is 500 pieces, which covers tooling amortization, material procurement, and batch processing. Prototype runs of 100–300 pieces are available with prototype tooling. Annual volumes above 10,000 units deliver the strongest per-part cost advantage.
Q: How long does it take to get custom MIM parts?
From design freeze to first-article delivery: 10–14 weeks. This includes tooling design (2 weeks), mold fabrication (4–6 weeks), process development (2 weeks), and first-article sampling with inspection (2–3 weeks). After first-article approval, production lead time is 4–6 weeks per order. See our MIM lead times page for details.
Q: Who owns the tooling for custom MIM parts?
The customer owns the tooling. Molds are stored at Emitech for the duration of the production program. If production ends, the tooling can be shipped to the customer or stored at Emitech with prior arrangement.
Q: Can I get a sample before committing to full production?
Yes. For programs above 20,000 units per year, we recommend a prototype phase using prototype tooling (100–300 samples) to validate geometry, material properties, and fit before investing in multi-cavity production tooling. Prototype lead time is 6–8 weeks.
Q: How do you ensure custom MIM parts meet specifications?
First-article inspection includes full dimensional layout on a CMM, material certification with mechanical property testing, and density verification. Production lots include in-process SPC checks on critical dimensions and final inspection per the agreed sampling plan. Documentation packages include material certs, dimensional reports, and lot traceability records.
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Nanjing Emitech delivers MIM from tooling through sintering and finishing. Custom MIM parts · MIM services · Request a quote