What is a Vacuum Chuck Holding System?
The basic principle of vacuum chucking involves the science of the atmosphere around us. Normal atmospheric pressure, at sea level, is just under 15 pounds per square inch. That means if we create a vacuum, such as a vacuum chuck, the barrier between the atmosphere and the vacuum, in this case our turning, has a pressure exerted upon it by the atmosphere. Vacuum is measured in inches of mercury or hg. A perfect vacuum is 30 inches of mercury (30 hg) and cannot be obtained on the surface of the earth. Most of the small pumps we use for our type of work are able to provide 22 to 28 hg, and this level of vacuum is more than sufficient for our purposes. In round numbers, the pressure exerted by the atmosphere is about one-half pound of force per square inch for every inch of mercury. This sounds confusing. Your system will have a gauge that reads from 0 to 30 hg. Divide the number on the gauge in half to find the pounds per square inch of force exerted on the turning. As an example, you ha
