With a tensile strength of 180,000 psi, these alloy steel screws are among the strongest we carry. They are stronger than Grade 8 steel screws and more than two and a half times stronger than stainless steel screws with split lock washer. The split lock washer helps to resist vibration.

A freely rotating washer distributes pressure over a wider area than a flange, preventing damage to your material's surface.

Prevent unwanted removal, leaks, and contamination with these sealing Torx screws.

With an O-ring under the head, these screws prevent leaks and seal out contaminants.

Made from stainless steel, these screws have good chemical resistance and may be mildly magnetic. All have a washer with sharp external teeth that dig into surfaces for maximum holding power and vibration resistance. Also known as Sems screws, the washer rotates freely but is permanently attached.

These metric screws have a washer with sharp external teeth that dig into surfaces for maximum holding power and vibration resistance. Also known as Sems screws, the washer rotates freely but is permanently attached.

These stainless steel screws have good chemical resistance and may be mildly magnetic. The washer has sharp internal teeth that dig into surfaces to resist large amounts of vibration while the smooth outside edge provides a finished look. Also known as Sems screws, the washer rotates freely but is permanently attached.

Sharp internal teeth dig into surfaces to resist large amounts of vibration, while the smooth outside edge provides a finished look. Also known as Sems screws, the washer rotates freely but is permanently attached.

These metric stainless steel screws have good chemical resistance and may be mildly magnetic. A curved washer protects delicate surfaces while providing constant tension. Also known as Square Cone Sems screws, the washer rotates freely but is permanently attached.

The flat washer distributes holding pressure and protects delicate surfaces from damage while the split lock washer adds tension to prevent loosening from small amounts of vibration.

When compressed, the split lock washer flattens to add tension and prevent loosening from small amounts of vibration. Also known as Sems screws, the washer rotates freely but is permanently attached.

To prevent unwanted removal, these screws have a tamper-resistant Torx drive—also known as a pin-in Torx drive—that makes them difficult to unscrew without special tools. An O-ring under the head blocks leaks and seals out dust and dirt.

These metric screws have a silicone O-ring that prevents leaks and seals out contaminants. Made from 18-8 stainless steel, they have good chemical resistance and may be mildly magnetic.

A nylon patch bonded to the threads adds friction to resist loosening from vibration.