Chicago Pneumatic 785S 18-Gauge Heavy Duty Air Shears 2,400 SPM. Powerful 1/2 hp air motor resists stalls and conserves energy. Triple idler planetary gearing for smooth operation and extended tool life. Ergonomic handle design for operator comfort. Heavy duty shear head provides long life and reliable cutting performance up to 18 gauge steel. Applications: Cutting squares and angles in materials such as aluminum, tin and steel. Strokes per minute: 2400.