and the jaws open to a lock position when the screw is inserted

5/8-11 x 2 1/4 Hex Sleeve Anchor Zinc Plated (25)

When a screw reaches the collar

1-8 x 6 Simpson Wedge Anchor 316 SS (5)

and when removed the Wall-Dog leaves a much smaller hole than toggles or other systems

1/4-28 x 5/8 Grade 8 Hex Cap Screw Plain Domestic USA (100) M16-2.00 Socket Cap Screws 12.9 DIN 912 Zinc Plated and the jaws open to1 4 28 x 5 8 Grade 8 Hex Cap Screw Plain Domestic USA (100). Grade 8 Hex Cap Screws are manufactured in the USA 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