Hex flange bolts, also known as hex head screws or hex flange bolts, are often used in construction and manufacturing applications that require high strength. These bolts have a hexagonal head and flange that provide additional surface area to secure parts, making them ideal for applications that do not require a flush fit.

Here are some of the key features of hex flange bolts:

1. **Head Type**: The head is usually hexagonal, which is convenient for using a wrench or socket. This makes it easier to tighten and loosen compared to other types of bolts, such as cross-head or flat-head bolts.

2. **Flange**: The flange at the bottom of the bolt provides additional support and prevents the bolt from sinking into softer materials such as wood, concrete, or masonry. This feature helps ensure a safer, more stable connection.

3. **Thread Type**: Hex flange bolts are available in different thread types, including metric (ISO) and imperial (UNC/UNF), and they can be coarse or fine threads depending on the application requirements.

4. **Material**: They are usually made of steel, stainless steel, brass, or other durable materials, depending on the application needs. Stainless steel is particularly useful in corrosive environments due to its resistance to rust and corrosion.

5. **Size**: The size of a hex flange bolt is usually specified by its diameter and length. Common sizes range from small sizes (eg M4 x 10mm) to large sizes (eg M16 x 50mm).

6. **Thread Length**: The thread length is usually longer than the bolt body, allowing for full engagement with the nut when fully tightened. This ensures maximum strength and durability.

7. **Application**: They are widely used in various industries such as automotive, construction, machinery, furniture assembly, etc. They are suitable for applications that require a combination of strength and stability, especially those where there is a risk of vibration or movement.

When selecting a hex flange bolt, consider factors such as material compatibility, environmental conditions, load-bearing requirements, and specific application needs to ensure optimal performance and service life.