This is a square that you can use with confidence, day in day out. Designed and constructed for everyday use, this reliable square should always be close to hand at the top of your toolbox. The British standard BS3322 for carpenter's squares only specifies 0.01mm per 10mm, squareness on the inside edges only; these Axminster Precision squares go one better. The square has a sapele stock, with a double-waxed finish. Heavy gauge, solid brass facing strips protect both working faces of the stock. The blade is stainless steel, with precision ground edges, top and bottom. The blade and stock have a triple brass rivet fixing for permanence. The inside and outside faces of the stock and the edges of the blade are guaranteed parallel. This quality construction ensures that the square is square, whether you choose to use it internally or externally.