| 1. Physical Properties
 | Elastic Modulus | Bend Resonance Method | 298 ~ 318 [GPa] | n=1 / Material Intrinsic Value (not routinely measured) c = 0
 | 
            
              | Poisson's ratio | 0.28 ~ 0.30 | 
            
              | Coefficient of Thermal Expansion | Optical Interferometry | 2.9 ~ 3.2 [x10-6/deg c] | 
            
              | Thermal Conductivity | Laser Flash Method | 18 ~ 25 [w/mk] | 
            
              | Constituent Phase | X-ray Diffraction Method Cu K α | No residual alpha phase peak | 
            
              | 2. Mechanical Properties
 | Density | Archimedes's Method | 3.22 ~ 3.26 [Mg/m3] | n=5 / Manufacturing lot c = 0
 | 
            
              | Hardness | Vicker's Method 196, 1N - 30sec, (ASTM F 2094) | 1400 ~ 1750 [HV] | n=3 / Manufacturing lot c = 0
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              | Rupture Strength | 3-point Bending Test (J|S R1601) | Min.735 [MPa] | n=20 / Material lot (powder lot) | 
            
              | Toughness | |F Method 196, 1N - 30sec, (ASTM F 2094) | 6 ~ 8 [MPa·m1/2] | n=3 / Manufacturing lot c = 0
 | 
            
              | 3. Internal Defect | Metallograph x200 | To not have following inside (cross section) of blanks 
                  Inclusions over average diameter of 15um (excluding sintering additive element)Voids over average diamante of 10umWhite or Black Color discoloration : Less than half of Grinding Allowance | n=5 / Manufacturing lot * In case the shipment qty is 1kp or less, n=3 / Manufacturing lot c = 0
 | 
            
              | 4. Crack | Fluorescent Penetrant Test (Visual inspection under UV lamp after immersion to fluorescent penetrant washing and drying) | No Crack | One Hundred Percent Inspection | 
            
              | 5. Appearance | Visual Check / Boundary Sample (Depth of chipping and height of protrusion on boundary sample will be produced by using depth of focus method of metallograph,) | 
                  Chipping/dent : Depth of less than 0.15mm (Length and Width will be allowed)Protrusion : Height of less than 0.20mm (Length and Width will be allowed)Attachment of foreign particles : will be allowedForeign substance on surface : will be allowedRoughing of surface : Same as chipping/protrusionColor unevenness : will be allowedDie Mark : Same as chipping/protrusion | One Hundred Percent Inspection | 
            
              | 6. Dimension | Micrometer | ![]() Equator Band Diameter (Diagonal diameter of equator band to be not subject of specification) | Diameter variation 0.15mm (~3/8") 0.20mm (13/32" ~)
 n=5 / Manufacturing lot
 c = 0
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Material Lot
Silicon Nitride powder lot that can assure uniformity of material characteristicManufacturing Lot
Dispatch lot that can assure uniformity of manufacturing record