25.4mm Diameter, 12.7mm Through Hole, Sapphire Window

Product Details 25.4mm Diameter Sapphire Substrates 3.2 – 19.1mm Through Hole Diameters High Transmission From 0.33 – 5.5μm Sapphire Windows with Through Holes, also referred to as sapphire washers, feature 25.4mm diameter sapphire substrates with a centered through hole ranging in diameter from 3.2 – 19.1mm. Sapphire offers extreme surface hardness second only to diamond , high thermal conductivity, and is chemically inert, making it ideal for use in harsh environments. These windows provide high transmission from 0.33 – 5.5μm and can be made much thinner than glass windows due to the structural strength of sapphire. Sapphire Windows with Through Holes can be manufactured as modified standard versions of our sapphire windows or as entirely custom products; please contact us to discuss your application requirements. Specifications General Type: Protective Window Type of Window: Crystal Physical & Mechanical Properties Diameter (mm): 25.40 ±0.127 Thickness (mm): 1.00 ±0.127 Parallelism (arcmin): ≤3.5 Bevel: Protective as needed Poisson’s Ratio: 0.27 Young’s Modulus (GPa): 435 Knoop Hardness (kg/mm 2 ): 1,900.00 Knoop Hardness (GPa): 1,900 Through Hole Diameter (mm): 12.70 ±0.127 Optical Properties Coating: Uncoated Substrate: Many glass manufacturers offer the same material characteristics under different trade names. Learn More Sapphire (Al 2 O 3 ) Index of Refraction (n d ): 1.77 Surface Quality: 80-50 Abbe Number (v d ): 72.24 Surface Roughness (μm): 0.1 per Inch Birefringence (n o -n e ): 0.008 for Visible Light Orthogonal to Optical Axis Axis Orientation: Random Wavelength Range (nm): 330 – 5500 Surface Flatness (P-V): 2λ (typical) Material Properties Density (g/cm 3 ): 3.97 Coefficient of Thermal Expansion CTE (10 -6 /°C): 8.8 Regulatory Compliance RoHS 2015: Compliant × Certificate of Conformance: View × Reach 247: Compliant ×