This is a handy set to have around. Each square is finely ground steel. All have common beam and blade widths and thicknesses which will allow them to be used in combination. 2", 3", 4" & 6" squares. These inexpensive steel squares are great for setting up power tools. The smallest (2 inch), is perfect for checking the squareness of scroll saw blades to the table. The larger squares are used for checking the blades on bandsaws, tablesaws and radial arm saws.