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

1/4 x 1 1/4 Mushroom Spike Zinc Plated (100)

3/4-10 x 6 Grade 8 Hex Cap Screw Yellow Zinc Plated

They are actually stronger than most metal and chemical anchors because the all plastic plug bonds through friction to concrete

Designed for use with 18-8 stainless steel screws

1-14 x 8 Grade 8 Hex Cap Screw Yellow Zinc Plated 9/16-18 Grade 8 Hex Cap Screws Yellow Zinc Plated Marine screws are locked in1 14 x 8 Grade 8 Hex Cap Screw Yellow Zinc Plated . Grade 8 Hex Cap Screws are manufactured from medium carbon alloy steel. In diameters 1 4 to 1 1 2 inches our Grade 8 material meets or exceeds SAE J429 Grade 8 specifications. Diameters over 1 1 2 inches meet or exceed ASTM A354 Grade BD. All material is manufactured with rolled threads. Yellow zinc plated bolting will meet or exceed ASTM F1941. Typical hardness on diameters 1 4 to 2 1 2 inches is