These vices have rugged, machined, double guide rods and single-lead Acme screws.
The regular front vice is 175mm(7") x 375mm(14.3/4") overall with a 22mm(7/8") dia. screw and clamping capacity of 210mm(8.1/4") (less the thickness of your wooden jaws).
The large front vice is 265mm(10.1/2") x 533mm(21") overall with a 28mm(1.1/8") dia. screw, and 330mm(13") clamping capacity (less the thickness of your wooden jaws). The larger vice has an offset centre screw to allow vertical clamping without skewing. These powerful vices can be added to an existing bench or built into a new one. A turned wooden handle is available separately.-bg