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

split bolt anchor

1 1/4 x 18 ITM SDS Plus Hammer Drill Bit X-Cutter

1-8 x 9 1/2 Socket Cap Screw Alloy

The heavy construction affords efficient drilling in stainless steel and other hard materials

3/4-10 x 2 1/4 Socket Cap Screw Zinc Square Bugle Coarse Drywall Screws Black Phosphate Marine screws are locked in3 4 10 x 2 1 4 Socket Cap Screw Zinc . Alloy Socket Head Cap Screws from Brighton Best. Hardness of RC 38 43, meets or exceeds ASTM A574. Manufactured from heat treated alloy steel, 1960 series.