Internal teeth dig into the screw head while the smooth outside edge won't snag objects. Use with metric fasteners that have small heads, such as fillister and cheese head screws.

Slightly domed with an oversized outside diameter, these washers distribute your fastener's load over a larger surface area than other internal-tooth lock washers to limit damage to soft material.

Teeth on the outside edge of these metric washers bite into the screw head and joint for a tight grip.

To keep 90° countersunk screws from loosening in vibration applications, the teeth on these washers bite further into the screw head and joint than standard external-tooth lock washers for a more secure hold.

The teeth on these washers firmly grip heads of 82° flat head countersunk screws.