British And American Round Head Hex Screws

1/4-20 5/16-18 Sooth Standard 304 stainless steel British And American Round Head Hex Screws  Non tapping screw are Machine screw, the pieceworker to be fastened must be tapped with taps in the Screw hole in advance to match the screw threads. The difference between tooth screws and other screws depends on whether they can be used together with nuts. Tooth screws can be used with nuts. And relative to the screws of other teeth, there are self-tapping screws. The nut of this kind of...