MIM Manufacturing: What is MIM and μ-MIM®

What is MIM?

Metal powder injection moulding (MIM) is a metal manufacturing method in which a material called feedstock—a mixture of metal powder and a binder made of resin, wax, or other substances—is injected into a mould and then sintered. This process, known as MIM manufacturing, enables efficient production of complex metal components that are difficult to create using conventional methods. By utilizing MIM manufacturing, manufacturers can achieve both precision and scalability in producing metal parts.

MIM process

MIM Features

	Conventional MIM	Additional feature by μ-MIM®
Material	Difficult-to-work materials and high melting point materials are available. The surface roughness is lower than other powder metallurgy parts since the finer metal powder is applied. Stainless steel is mainly used.	Further improvement of surface roughness and dimensional accuracy by applying ultra-fine powder with a proprietary binder system. Titanium, titanium alloy, copper, copper alloy, precious metal, and other new alloy materials are also available.
Design	A high degree of design freedom (e.g. side holes, undercuts) compared to powder metallurgy parts. High transferability (e.g. small characters, complicated surface patterns). Thin wall structure. Feasible to change manufacturing method from lost-wax and CNC machining	Mass production of complex hollow shapes with 3D-μMIM®technology. Ultra-thin wall structure.
Injection moulding	Complex shapes with free curves.	Bi-colour moulding of MIM. Moulding with the same level of difficulty as plastic injection moulding.
Sintered body	The less quality variation between manufacturing lots. Excellent mechanical properties compared to general powder metallurgy parts due to the high relative density of 95% or more (in SUS). Various surface treatments, heat treatment and plating etc., are possible.	Achieves a level of accuracy that does not require secondary processing (except for some threads and so on).

Accuracy and specifications

		Conventional MIM	μ-MIM®
Material	Length	＜50mm	＜10mm　 Maximum 30mm in one direction
Material	Thickness	0.5～5mm
Minimum wall thickness		0.3mm(partial)	0.1 mm (6mm square)
Smallest hole size		0.3mm(partial)	Φ0.03mm
Tolerance	< 5mm	+/- 0.03mm	+/- 0.01mm
	5-10mm	+/- 0.04mm	+/- 0.03mm
	10-20mm	+/- 0.08mm
	20-30mm	+/- 0.15mm
Relative density(%)		95-98	> 98.5
Surface roughness (Ra)		< 3μｍ	0.3μm（In case of applying ultra fine powder）
Rmax		< 10μm	2～10μm
Product weight		< 50g	≦ 10g

What is μ-MIM®?

μ-MIM® is an advanced technology in MIM manufacturing that enables the production of ultra-precise MIM components. This technology focuses not only on miniaturizing product size but also on ensuring high accuracy and quality.

μ-MIM® meets the following demands in MIM manufacturing:

・Mass production of components and materials that are difficult to machine
・Integration of small components that are difficult to assemble
・Mass production of components with size and tolerance requirements that are challenging in conventional MIM manufacturing
・Adding value to components by integrating multiple functions

In conventional MIM manufacturing, most parts range from several millimeters to several centimeters and must satisfy dimensional tolerances of about 5–10% of the part size. With μ-MIM®, even smaller products with stricter tolerances can be mass-produced, overcoming the limitations of standard MIM manufacturing.

μ-MIM Dimensional accuracy and product size