Grades of Sapphire
Refractory Metals - Composites -Special Alloys - Ceramics -Tungsten - Titanium
SINGLE CRYSTAL SAPPHIRE
Sapphire is grown by two methods: either in boule form, up to 8" in diameter, or it can be drawn from a melt in a wide variety profiles such as tubes, rods or sheets. Boule grown or Czochralski material is clear, free of seeds or bubbles striates and can be machined into a wide range of shapes for windows, substrates, and other engineered parts. Sapphire that is pulled from a melt through a profile is suitable for many applications at an economical price and is available in much longer lengths.
Boule Grown Sapphire Each sapphire component is custom manufactured to exacting standards. Parts as large as 8" diameter and as small as a few mm cross section can be made using boule grown materials. This material is available in a number of crystalographic orientations.
Profile Grown Sapphire Profile grown materials can be made with simple cross sections. Rods are available from 0.3 to 5 mm diameter and up to 1800 mm long. Tubes are available from 2.0 to 25 mm OD with wall thickness from 0.5 to 1.5 mm and lengths from 300 to 1800 mm. Ribbons are available 100 mm wide and from 0.4 to 2.0 mm thick with lengths to 700 mm.
Sapphire Table of Properties (pdf 43k)
Grades of Sapphire
Optical Grades (1 - 4)
Grade 1
Inclusions, block marks, twins, micro-bubbles and dispersal centers are non-existent.
Grade 3
Inclusions, block marks and twins are non-existent. Uniformly distrubuted bubbles by size; not larger than 50 microns and not closer than 500 microns are admitted.
Grade 4
Inclusions, block marks and twins are non-existent. Bubbles with total diameter not larger than 200 microns and not closer than 20mm are admitted.
Technical Grade
Grade 5
Inclusions, block marks and twins are non-existent. Uniformly distributed bubbles by size; less than 50 microns and not closer than 500 microns. Also, bubble concentration not larger than 500 microns and not closed than 20 mm are admitted.
Industrial Grade
Grade 6
Inclusions, block marks and twins are non-existent. Bubbles not larger than 50 microns with a total diameter less than 200 microns and not closer than 20 mm are admitted.
