Tail vices are very handy when installed on a workbench as they can allow for the clamping of long and wide workpieces. It is best to mount with the vice assembly in the bench and an L-section extending to the edge of the bench so that the screw doesn't get in the way.
This vice screw has a working size of 330mm jaw opening and allows for jaw size of at least 73mm thickness (please note that this allows for two jaw thicknesses of at least 36mm).
Ensure that when just using the screw to create your tail vice that extra reinforcing will be necessary to prevent sagging over time. You can also purchase the Tail Vice & Mount which has mounting brackets that resolve this issue. The vice screw uses a 29.5mm bright steel bar with a deep cut thread (for positive clamping pressure) and cast iron fittings.