Factory directly Flat Head Concrete Screws - White Concrete Self Tapping Undercut Bolt, Hex Head Screws, Under Cutting End, Zinc Plated, More Stronger For Concrete, Grade Can Be 4.8/5.8/6.8/8.8/10.9/12.9 Etc. – Gusen

Crack concrete/concrete C20/25-C50/60.
Celling and roofing.
Crack concreteC12/15
Natural marble/stone.
Solid bricks.

high-strength masonry screw anchors and are approved for use in cracked and uncracked concrete.

Concrete screws are hardened screws with a double lead—consisting of alternating raised and lowered threads with notches cut into the raised threads—and a diamond-shape, nail-type point. Special carbide bits are recommended for drilling pilot holes prior to driving concrete screws into masonry.
Also known as masonry screws, concrete screws cut their own threads when used in concrete, block, or brick. They can be used to secure wood, metal, or other materials, and eliminate the need for an anchor when used in light- to medium-duty applications.

Qualified for static and seismic loading conditions.

Thread design undercuts to efficiently transfer the load to the base material.

No special drill bit required; designed to install using standard-sized  drill bits.

Concrete anchor is a high-strength screw anchor for concrete and masonry. It is designed for optimum performance in both cracked and uncracked concrete.

Hex-washer head requires no separate washer and provides a clean installed appearance.

Handrail ventilating pipe
Wall curtain wood structure
Window/door metal profiles
Ladder mechanical device
Celling cable bridg

Concrete /light concrete/solid bricks/honeycomb bricks/natural stone/concrete bricks/sand bricks

1, drill
2, clean
3,install
4, finish