Home > Tool Sets > Adjustable Square Set Now Availaible in a set. Four inch and six inch. Also called double squares, these are as accurate as machinist's squares and as adjustable as combination squares. They are very useful in laying out small work. 3032000$37.00 6 inch Adjustable Square Also called double squares, these are as accurate as machinist's squares and as adjustable as combination squares. They are very useful in laying out small work. 3031006$22.95 4 inch Adjustable Square Also called double squares, these are as accurate as machinist's squares and as adjustable as combination squares. They are very useful in laying out small work. 3031004$15.95