Use Workstops Whenever Possible – Side loads are the enemy of vacuum applications! Though vertical holding force may be high, cutting forces can shift a part sideways, especially when machining plastics with a low friction coefficients (nylon, teflon, delrin).Short and wide parts that absolutely cannot be held with a vise are the best candidates for vacuum workholding. Use Common Sense – Holding a part that is 1 inch square and 4 inches tall is not going to hold up against cutting forces.For example, a 3' square workpiece will only be held with 126 lbs of downward force and a 10' square workpiece is held with 1,400 lbs. A vacuum chuck may be your only choice, but don’t expect to be able to machine a part as aggressively as when using a vise. Vacuum Workholding is Often a Secondary Choice – Yes, vises and clamps are the preferred method of holding a workpiece due to theoretically unlimited clamping force, however thin parts aren't easily held with a vise.This is because the weight of air around us is what actually pushes the part down onto the chuck. Vacuum Power has an Upper Limit – The absolute maximum vacuum power any vacuum pump can achieve on Earth is 14.9 pounds per square inch at sea level.

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