Installation methods: Select a chopping bit with the same diameter as expansion casing, and install it on the electric drill for punching. M6 male thread Expansion hook anchor bolt with flat washer and hex nut. The depth of the hole should be equal to the length of the bolt. Closed hook bolts suitable for secure and reliable fixing of items and fixtures to concrete, brick, walls and any solid . Then insert the expansion bolt set into the hole., Manufacturer: Mcnhbdgg