Dear Forum, I am currently trying to buy some imperial machine screws and bolts online, and I am confused with how the diameter is given. The website I am seaching (boltdepot.com) gives me these diameters but I don´t understand what is meant by i.e. "2-56" 2-56 4-40 6-32 8-32 10-24 10-32 12-24 1/4-20 5/16-18 3/8-16 1/4-28 Can anyone help me? I am specifically looking for a 5/32 inch diameter screw but this does not appear here. Anyone suggesting a different good site for buying fasteners online, preferably located in europe? best regards t.