Wilton 14142 104, 100 Series Forged C-Clamp-Heavy-Duty, 0-Inch-4-Inch Jaw Opening , 2-1/4-Inch Throat Depth Recommended For Heavy Industrial And Construction Job Site Demands, The Heavy-Duty Models Are Some Of The Toughest Products Available 100 Series Model Frames Are Forged Of Superior Quality Steels Forged Square Head Spindle With Rolled Thread. Black Oxide Coating For Added Strength