Use these Class 10.9 steel screws for high-stress applications, such as valves, pumps, motors, and automotive suspension systems. They are at least 25% stronger than medium-strength steel screws. The flange distributes pressure where the screw meets the surface, so you don’t need a separate washer. All screws meet ISO or SAE specifications for material quality. Head height includes the flange. Length is measured from under the flange.

Zinc yellow-chromate plated steel screws resist corrosion in wet environments. They’re a good choice for most applications.

Steel screws are best for dry environments, since moisture will cause them to rust. They require little surface prep before applying a finish, so you can apply your own paint or coating.

Black-phosphate steel screws are mildly corrosion resistant in dry environments.

Match the thread spacing of mating components. Coarse threads are the industry standard; choose these screws if you don’t know the threads per inch. Fine and extra-fine threads are closely spaced to prevent loosening from vibration; the finer the thread, the better the resistance.

Screws that meet ASME or DIN specifications are made to strict dimensional standards.