Usage Tips:M6 male thread Expansion screw hook anchor bolt with flat washer and hex nut. Closed hook bolts suitable for secure and reliable fixing of items and fixtures to concrete, brick, walls and any solid surface. Installation methods: Select a chopping bit with the same diameter as expansion screw casing, and install it on the electric drill for punching. The depth of the hole should be equal to the length of the bolt. Then insert the expansion bolt set into the hole. Remember: Do not screw off the nut and prevent the bolt from falling into the hole when the drill is too deep. Tighten the nut for 2 to 3 buckles and unscrew the nut when expansion bolt si very tight without any looseness. Then the fixed items are mounted with perforated fixed part and installed aiming at bolt. The gasket or spring washer outside is used to screw the nut tightly. Product Name: Expansion Hook Bolt Main Color: Silver Tone Expansion screw total length: 60mm Expansion tube length: 40mm Ring nut length: 34mm Outside diameter: 34mm Material: 304 Stainless Steel Weight: 136g Package Contents: 2 x Expansion Hook Bolt Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.