Those of you that have Abwood vices may want to give them a check over now and then. I've just had to repair my second Abwood that had a fracture in the exact same place as the first one. Neither are new, and both had been used in toolrooms for a long time before I had them.
They both cracked on the cast base to the rear of the bronze nut, with
2 cracks fanning out at about 90 degrees between them, from the bore for the nut to the radiused corners where the slideways meets the relieved section that runs towards the back. The crack on both had also propagated across the wall of the nut bore, about 1/2" down inside it..
The cause is fairly obvious I think. Neither vice had the retaining screw present (can be easily seen on the underside if present) that holds the bronze nut in place, and overtightening of the vice allows the nut to tilt up and back a bit and bear heavily on the back wall of the bore, which causes it to crack.
The repairs were quite simple, having caught them both in time before a piece actually cracked out of the casting. However, it could have been either inconvenient or dangerous if it had cracked during a rush job or broken off during the course of a cut.
Well worth spending 10 minutes to take it apart and check IMO.
Peter