These nuts tighten when turned to the left. Use them with left-hand rods and screws to prevent counterclockwise-moving parts from loosening.

About half the height of standard-profile locknuts, these fit in spaces with low clearance. You can also use them as jam nuts by threading them against a hex nut to hold it in place. The nylon insert grips the screw to prevent loosening from moderate vibration without damaging threads. However, the insert may become brittle if exposed to high temperatures. These locknuts are reusable a handful of times, but the holding power decreases with each use.

These nuts are manufactured and tested to strict U.S. military standards for material and construction. About half the height of standard-profile nuts, they fit in spaces with low clearance. You can also use them as jam nuts by threading them against another hex nut to hold it in place.

About two-thirds the height of standard flex-top nuts, these fit in spaces with low clearance. You can also use them as jam nuts by threading them against a hex nut to hold it in place. The top section expands to grip the screw on all sides for a stronger hold than both nylon-insert and distorted-thread locknuts. As a result, they're suitable for use in equipment with constant, vigorous vibration, such as engines. These locknuts are reusable a handful of times, but the holding power decreases with each use.

These nuts tighten when turned to the left. Use them with left-hand rods and screws to prevent counterclockwise-moving parts from loosening. About half the height of standard-profile nuts, these fit in spaces with low clearance. You can also use them as jam nuts by threading them against another hex nut to hold it in place.

Twist the slip-resistant head by hand, then insert a T-handle hex key into one of the holes to apply extra torque for a tight fit. Nuts have a low-profile head that fits into cramped spaces. You can also use them as jam nuts by threading them against another nut to hold it in place.

Twist these thumb nuts into spaces without a lot of clearance. They have a short, slip-resistant head, so you can grip them easily and make controlled adjustments in cramped spots. You can also use them as jam nuts by threading them against another nut to hold it in place.

About half the height of standard-profile locknuts and 10% wider, these fit in spaces with low clearance and handle heavier loads by distributing them over a larger area. You can also use them as jam nuts by threading them against a hex nut to hold it in place. The nylon insert grips the screw to prevent loosening from moderate vibration without damaging threads. However, the insert may become brittle if exposed to high temperatures. These locknuts are reusable a handful of times, but the holding power decreases with each use.

Apply extra torque to these nuts to prevent accidental loosening. Twist them on by hand, then crank with a wrench for a tight fit. The flange distributes pressure evenly across the mounting surface without the need for a separate washer. These nuts are often used to secure screws in oversized or irregularly shaped holes since the flange covers a larger area than standard nuts.