Editing Steel square (section)

== Body and tongue ==
In traditional [[timber frame]] joinery, [[Mortise and tenon|mortises and tenons]] were typically {{convert|50|mm}} wide and {{convert|50|mm}} from the edge of the timber when working with softwoods, giving rise to the width of the body. Likewise, mortises and tenons were traditionally {{convert|37|mm}} wide when working in hardwoods, explaining the width of the tongue. This allowed for quick layouts of mortise and tenon joints when working both hard and softwoods.