1. Expansion Anchors (Mechanical Anchors):

* Used to fix brackets or frames to concrete structures.
* Expand inside the drilled hole when tightened, locking the bolt in place.
* Commonly used for securing curtain wall brackets to concrete or masonry.

2. Chemical Anchors (Resin Bolts):

* Bond bolts into concrete using chemical adhesives.
* Ideal for high-load connections with strong resistance to vibration.
* Used in critical fixing points in curtain wall systems.

3. Through Bolts :

* Pass completely through materials, with a nut on the opposite side.
* Used to join thick sections such as steel plates or brackets.
* Common in transom-mullion joints and bracket connections.

4. Hollow Wall Bolts (Toggle Bolts):

* Designed for use in hollow or lightweight materials, like drywall or thin panels.
* Also used to fix components inside *closed steel sections*where access to the opposite side is not possible.
* Not typically used for primary structural elements but helpful for non-structural or secondary fixings.

5. Self-Tapping Screws (STS):

* Cut their own threads into metal surfaces, eliminating the need for pre-drilling.
* Used for metal-to-metal connections such as attaching mullions to brackets.
* Fast and efficient for lightweight connections.