Fixed JointMaster Angle Joining 90° clamp features a retractable plate for edge alignment, V-grooves for securely holding round pieces. Perfect for holding two pieces of different thickness requiring individual adjustments. Works with any combination of both round and flat stock. Throat reach of 3" and a max. thickness of 3".  Similar to the PA634 other than the PT634 has a fixed setting. For metal working and joining.