Made of high grade alloy steel, hardened and ground from stabilized stock. All are 6" long and 1/8" thick. All are within .0002" parallelism and height. Hardness 50-54HRC. 1 PAIR 3/16X1X6 W, 5/16 HOLE 1 PAIR 3/16X1-1/4X6 W, 3/8 HOLE 1 PAIR 3/16X1-1/2X6 W, 6/7 HOLE 1 PAIR 3/16X1-3/4X6 W, 1/2 HOLE