An O-ring under the head prevents leaks and seals out contaminants.

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

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.