Hard to find a bag tougher than this, though at 4lbs empty you might not want to be carrying this all day.
… constructed with #8 canvas duck. The top opening has a steel frame to keep the bag open and provide security when closed. Two leather straps secure the opening. @” web handles wrap around the entire bag fro added strength. They have a “box X” stitch at the top for extra strength. The bottom is reinforced with heavy vinyl coated nylon and has a double tempered masonite board. Six brass studs are placed on the bottom of the bag to protect against abrasion.
See more at the ESTEX Manufacturing Company