PI-WIKI-MET-13 · Advanced Metallurgy · reviewed 2026-10-31
MIM Revolution in Aerospace Body Jewelry Explained
Critical numbers
MIM Theoretical Density AchievedApproaching full density with HIP [7]
MIM Density (no HIP)Typically about 96–99% [10]
Minimum Thread Diameter (2014)0.8 mm, believed to be a first for micro-MIM body jewelry
Minimum Wall Thickness Achieved< 0.5 mm
Surface Finish (as-sintered)Ra < 0.8 μm
Surface Finish (electropolished)Ra < 0.1 μm
HIP Conditions (316L)900–1,100°C at 100–200 MPa argon pressure
Sintering Temperature (316L)~1,300–1,380°C in hydrogen atmosphere
Sintering Shrinkage~15–20% linear
Metal Powder Particle Size5–20 μm
Metal Volume Fraction (feedstock)55–65% by volume
Tooling Life (steel mould)Typically hundreds of thousands of cycles
Do not
- Accepting "MIM" labelling without process verification
- Purchasing MIM jewelry without HIP specification
- Assuming all 316L is equivalent regardless of manufacturing process
- Using MIM feedstock compatibility as a proxy for jewelry quality
- Not distinguishing micro-MIM (body jewelry scale) from standard MIM
Applicable standards
- European Union — ISO 5832-1
- United States — ASTM F138-19
- ASEAN & Asia-Pacific — Thailand