Marine screws are locked in place thanks to their "teeth" (the thread indentations will resist back-out even after prolonged vibration)

1/2-13 Drop-In Anchor Zinc Plated (50)

you always enjoy a vast selection of various fastening solutions — TimberLOK® Heavy Duty Wood Screws included

3/4 x 7 Hex Lag Screw Zinc Plated

1/2-20 x 7 Socket Cap Screw Alloy

3/8-24 L9 Hex Nut Alloy Cadmium Yellow and Wax Coated Domestic USA (3000) M24-3.00 Socket Set Screws Cup Point DIN 916 Black Oxide Marine screws are locked in3 8 24 L9 Hex Nut Alloy Cadmium Yellow and Wax Coated Domestic USA (3000) . L9 High Tensile Strength Hex Nuts are designed for use in high stress, severe service environments. The highest mechanical strength off the shelf fastening system available, its special features control torque tension characteristics to develop high clamp loads when using properly controlled tightening methods. Brighton Best manufactures L9 nuts from AISI alloy steels. L9