These Eclipse Screw Clamps feature a 3-1/8" throat depth capacity and are manufactured to average clamping force of 660 lbs depending on the size. The sliding head quickly sets the clamp to the required capacity, whilst the serrated grooves on the corrosion resistant nickel plated bar prevent slippage in use. The cast iron malleable heads offer maximum strength and the wooden handle provides a firm and comfortable grip. Ideal for medium to heavy duty wood working applications.