Vacuum Workholding Mastery: Gasket Selection, Zone Control & Leak Prevention

The Physics of Vacuum Clamping

Atmospheric pressure exerts approximately 14.7 PSI (1 kg/cm²) at sea level. A 10" x 10" (100 sq inch) part clamped under a true vacuum enjoys over 1,400 lbs of holding force.

Onion-Skinning Small Parts

When machining small parts (under 100 sq inches), the lateral cutting force of a 1/2" bit can overcome the vacuum seal.

• Strategy: Leave a microscopic 0.5mm (0.020") onion skin on the bottom of the part during the main roughing cycle, maintaining full vacuum seal across the entire sheet.
• Final Pass: Execute a high-speed finishing pass at 6,000 mm/min with a 1/4" downcut bit to sever the thin skin without displacing parts.