A clamping fixture includes a gauge rod having a fixed and a movable jaw mounted thereon, a lever-like handle, and a shift plate having a lower slot, via which the gauge rod is extended. The shift plate is connected to a rear side of the movable jaw via two shafts having compression springs mounted thereon. When the handle is downward pulled, a roller on the handle pushes the shift plate to turn clockwise, bringing the slot into an inclined position to firmly press against the gauge rod and thereby becomes immovable to stop the movable jaw from moving. The handle has a nut engaged with a screw rod mounted on the movable jaw. When the screw rod is turned, the nut and accordingly the handle are axially finely adjusted until a workpiece is firmly clamped between the two jaws.
A bar clamp has an operating handle being in ratchet engagement with end teeth of a slide bar. The operating handle is adapted to pivot counterclockwise to cause a first clamping jaw carrier to displace along the slide bar and then pivot about a lock pin in the slide bar so as to displace a first clamping jaw a sufficiently large distance to securely clamp a workpiece by cooperating with a corresponding clamping jaw.
