edition, on page 346, states that all that matters is surface speed at

the periphery, and the tensile strength of the steel, and gives a

formula: V=Sqrt[10

***s], where V is surface speed in feet per second, and**

s is tensile strength in pounds per square inch.

Let us assume that s= 300,000 psi, the cited strength of ball bearing

race steel. Sqrt[10*300000]= 1732 fps.

s is tensile strength in pounds per square inch.

Let us assume that s= 300,000 psi, the cited strength of ball bearing

race steel. Sqrt[10*

A bearing 1.75 inches in diameter will have a circumference of

(1.75)(3.1416)/12= 0.4561 feet, so 1732 fps implies 3,781 rps, or

226,832 rpm.

The speed of sound is about 300 meters per second at sea level, or about

900 feet per second, so the surface speed of the outer race is 1732/900=

1.92 times the speed of sound at sea level.

If the airjet is at the speed of sound, and is impinging on the balls,

the outer race will go twice the speed of sound.

If the bearing has ten balls, the siren tone will be at 3,781*10= 37,810

Hz, well into the ultrasonic, as people have observed.

The guy that did the experiment showing a max speed of ~20,000 rpm for

whatever reason did not achieve full speed, as 20,000 rpm isn't nearly

enough, and yet people have no problem causing bearings to burst from

overspeed.

Basically, it all fits together. Then it bursts.

Joe Gwinn