The forged jaws of this thumbturn pipe wrench tighten as you apply torque to the pressed steel handle — and the jaws continue to tighten as you increase the force. The knurled thumbscrew provides a convenient way to adjust the wrench without changing your grip.
Patented back in 1875, this wrench has been around over 100 years. While the design seems sound, you have to wonder why it isn’t more commonly used.
Currently manufactured by Footprint Tools, the wrench is available in 7″, 9″, and 10″ lengths. It looks like the 9″ wrench runs about $20 and the 12″ wrench runs $40.