Square nut DIN 557

steel

6.7 mm, 8.7 mm, 11.5 mm, 15.5 mm, 17.2 mm
(0.26 in, 0.34 in, 0.45 in, 0.61 in, 0.68 in)

4 mm, 5 mm, 6.5 mm, 8 mm, 10 mm
(0.157 in, 0.197 in, 0.256 in, 0.315 in, 0.394 in)

8 mm, 10 mm, 13 mm, 16 mm, 18 mm
(0.31 in, 0.39 in, 0.51 in, 0.63 in, 0.71 in)