These cabinetmaker's squares are used to lay out or transfer measurements quickly and accurately; you always have an ample reference face against your work without having to flip the square. This also simplifies working in two axes at once (e.g., measuring in 50mm and over 40mm), substantially reducing the chance of error when measuring and marking two dimensions.
The stainless steel blade is 75mm wide and 150mm long, machine ground on all four edges and graduated to 100mm along both edges and across one end to 70mm. The Imperial model is graduated to 4" along both edges and across one end to 3".
The diamond cut-out in the blade holds a pencil tip in position and makes it easy to draw lines parallel to an edge. The locking mechanism has a notched pin like those on combination squares, with the blade bearing on polished, hardened steel reference pins set in the body. Accurate and well made.
22 June 2015
Very useful addition to a traditional sliding square or a combination square69 mm and less are common widths for me when making frames, and this square makes it easy to transfer these dimensions across the wood. Setting a distance using the scales on the blade I find less easy and a trifle less exact than on a well made traditional sliding square (like the one manufactured by Starret). Apart from this square lacks 1/2 mm markings, the stock flexes a bit when slided. So both scales of the long edges need to be checked before tightening the locking screw.