Summary: square 6 long for your day to day work. Another shorter square 3 or 4 long could also be handy for your woodworking tools box. Tip : The Nobex Adjustable Miter Square When you look for a good square - please check the Nobex Quattro adjustable miter square. I came across one some months ago at a friends workshop and found it very handy
Image Dimensions: 200 x 144
Image originally found here.