Wilton 14554 4-Fc, "O" Series Bridge C-Clamp-Full Closing Spindle, 0-Inch-4-1/2-Inch Jaw Opening, 2-3/4-Inch Throat Depth The Full Closing, Extra Heavy Duty Models Are Designed To Stand Up To The Demands Of Heavy Industrial Applications Like Those In Ship Building Hot Upset Square Head On Spindle Withstands Higher Torque Square-Head Spindle Has Large Diameter Rolled Thread And Hardened Point Which Provides Smoother Operation And Added Strength