Bal-tec™ Home Corner Cube Spheres
These balls have a large diameter, blind bore that is usually quite deep. They often, but not always, have threads in this blind bore or in the center of the flat bottom surface. The majority of the corner cube spheres are either one and one half inch (1.500”) [38.1mm] diameter or seven eights of an inch ( ⅞”, 0.875”) [22.23mm] diameter or one half of an inch ( ½”, 0.50”) [12.7mm] diameter.
Corner cube spheres can be custom produced in any diameter with any diameter bore and any thread desired by the customer. The material normally used to produce the Corner Cube Spheres is type 420 stainless steel. In the heat treated condition, this material is very hard, but still maintains a high magnetic permeability so that it is strongly attracted by a magnet.
There are occasions when a customer wants a higher than normal hardness, in which case, the balls are made of type of 440C stainless steel. The very high standard quality for our corner cube sphere is AFBMA-Grade 25. This means that these balls are spherical within 25 (twenty five) micro inches [0.000635mm](635 nanometers) and have a surface finish of one point five (1.5) micro inches [37.5 nano meters] Ra maximum all the way out to the lip. This is two to four times what other companies claim and four to ten times what they actually produce. The sphericity of our balls is measured and documented with a Taylor Hobson/Talyrond, to an uncertainty of one micro inch. This is a sophisticated electromechanical measuring system with a current replacement cost of almost half a million dollars.
The measuring accuracy of the Talyrond system is directly traceable to NIST and to fundamental natural standards, (see our authenticator line of calibration instruments), reference “reversal technology”. The dimensional tolerance of our corner cube spheres is plus or minus one hundred millionths of an inch [0.00254mm]. Many of the manufacturers of ball mounted corner cubes use a threaded aluminum sleeve to hold the corner cube in the cavity of the sphere. The threads on these aluminum sleeves are quite fine, which makes the pitch diameter of the thread very critical. In order to facilitate interchangeability, we typically hold a 0.0002 inch [0.0015mm] tolerance on the pitch diameter of the thread. This quality is way beyond the ability of most machine shops. Actually 0.0002” pitch diameter tolerance, is way beyond almost any machine shop’s ability to even measure it. With all of this emphasis on quality, you would expect the cost of these premium products to be very high. Actually just the opposite is true.
We sell these to the corner cube manufacturers, we do not sell complete corner cubes reflectors.
|Aluminum sleeve||$ 12.00|
|Corner Cube Sphere||$ 40.00|