Made from Grade 8 steel, these screws can be used in high-stress applications, such as valves, pumps, motors, and automotive suspension systems. They are at least 25% stronger than medium-strength steel screws. Grade 8 steel hex head screws are marked with six radial lines. Length is measured from under the head.

Zinc yellow-chromate plated steel screws resist corrosion in wet environments.

Match the thread spacing of mating components. Fine and extra-fine threads are closely spaced to prevent loosening from vibration; the finer the thread, the better the resistance.

Screws that meet ASTM A354BD or SAE J429 comply with specifications and testing requirements for material quality.

Screws that meet ASME B18.2.1 or ASME B18.6.3 comply with specifications for dimensional standards.

For technical drawings and 3-D models, click on a part number.

With a tensile strength of 170,000 psi, these alloy steel screws are stronger than Grade 8 steel screws. Length is measured from under the head.

Black-oxide steel screws are mildly corrosion resistant in dry environments. Fine and extra-fine threads are closely spaced to prevent loosening from vibration; the finer the thread, the better the resistance. They are not compatible with coarse threads.

Screws that meet ASTM A574, ASTM A574M, and ISO 898-1 comply with specifications and testing requirements for material quality.

For technical drawings and 3-D models, click on a part number.