Hex head self-tapping wall screws are specialized fasteners designed for securing materials to walls without the need for pre-drilling. They have a hexagonal head, which allows for easy tightening with a wrench or socket, and a self-tapping feature that enables them to create their own threads as they are driven into the wall material. Here's a more detailed overview: 

HEX FLANGE HEAD SELF-DRILLING SCREW 5.5x25

Items Number : 000001

Part Number : AB-HSDS12-14L25E-DP3RC-S1000

Description : AB™ head mark hex flange head  wall screw 5.5x25 with EPDM washer, drill point type#3

Pack Qty (Pcs) : 3000 (Minimum sales quantity 3000 Pcs.)

A hex head flange self-drilling screw is a type of fastener designed for applications where the screw needs to drill its own hole and create threads in the material without the need for pre-drilling.

The application process for hex self-drilling wall screws in steel structures involves specific steps to ensure proper installation. Here’s a general guide for the application process in a steel structure in Bangladesh.

• Tooling:

1.  Use a power drill with the appropriate power and speed settings for drilling through the material.

2. Ensure the drill bit is suitable for metal drilling.

• Drilling Process:

1. If pre-drilling is required, use a drill bit that matches the diameter of the screw.

2. Align the drill with the marked point on the wall.

3. Apply steady, even pressure to the drill to create the hole.

4. For hex self-drilling screws, the screws are designed to drill through the material while creating their own threads. Pre-drilling may not be necessary, depending on the screw type and material.

• Inserting the Screw:

1. Insert the hex self-drilling wall screw into the drilled hole (if pre-drilling is required).

2. Apply downward pressure and start turning the screw clockwise using a hex key or wrench.

3. The self-drilling feature allows the screw to penetrate the material and create its own threads.

• Torque Control:

1. Gradually tighten the screw until it is snug. Be cautious/careful not to over-tighten, as this could damage the screw or compromise the integrity of the material.

•  Checking the alignment:

1. Ensure that the screw is driven straight into the material. Misalignment can affect the integrity of the joint.

• Repeat the Process:

1. If you are installing multiple screw, repeat the process for each screw, ensuring consistent installation.

• Post-Installation Inspection:

1. Inspect each installed screw to ensure they are securely fastened, and there are no issues with alignment.

• Documentation:

1.  Keep records of the installation locations, screw sizes, torque values, and any deviation from the standard procedure.

Maximum 4 mm thick for #12, and #14 gauge

•  Use a hex socket H#8 (5/16‘‘)

• Use a mains-powered or cordless screwdriver with a drive speed of 2500 RPM maximum.

• Fit the driver bit into the screw and place it in the fastening position.

• Apply consistently firm pressure (end load) to the screwdriver until the screw has fastened