heavyduty Pipe Wrench has a cast iron handle & frame around the adjustable jaw made in a heavy I beam construction to ensure maximum strength & rigidity under load Drop forged steel jaws are hardened & tempered as is the knurled adjusting nut The lower jaw is precision seated to prevent excess load on the retaining pin Conforms to the most stringent US Federal Specifications Size 300mm 12in Jaw capacity 60mm 238in