Fischer Anchor Bolt

Product Description

Fischer anchor bolts are high-performance mechanical expansion fasteners used to secure heavy loads in concrete and natural stone. While the term is often used generally, it typically refers to their "Bolt Anchor" range, which utilizes a torque-controlled expansion clip to grip the drill hole wall.

The Fischer system is categorized based on the substrate condition and the required load-bearing capacity.

Key Mechanical Bolt Series

1. FAZ II (The Performance Standard)

This is Fischer's flagship "Option 1" anchor, approved for use in both cracked and non-cracked concrete.

• Design: Features a specialized expansion clip that allows for high load-bearing capacity even if the concrete cracks (which naturally occurs in tension zones).

• Seismic Rating: Approved for C1 and C2 seismic performance categories, making it suitable for earthquake-prone regions.

• Materials: Available in zinc-plated steel (gvz), stainless steel (R/A4), and highly corrosion-resistant steel (HCR) for tunnels or swimming pools.

2. FBN II (The Economic Choice)

A cost-effective expansion bolt designed specifically for non-cracked concrete.

• Versatility: Offers two anchorage depths—a standard depth for maximum load and a reduced depth to save drilling time and avoid hitting reinforcement bars.

• Application: Ideal for railings, consoles, and metal brackets where the extreme performance of the FAZ II isn't required.

3. FH II (High-Performance Sleeve Anchor)

A heavy-duty sleeve anchor designed for aesthetically demanding or high-shear applications.

• Mechanism: The entire sleeve expands along the hole, providing a massive surface area for load distribution.

• Finish: Often available with a countersunk head or a cap nut for a flush, clean appearance in visible architectural steelwork.

Technical Comparison

Installation Parameters

To achieve the rated load capacity, specific installation steps are mandatory:

1. Drill & Clean: Drill the hole to the specified diameter ($d_0$) and depth ($h_1$). The hole must be cleaned with a blow-out pump or vacuum; dust left in the hole can act as a lubricant and significantly reduce load capacity.

2. Drive: Hammer the anchor through the fixture (push-through installation) until the washer is flush.

3. Torque: Tighten the nut to the specified installation torque ($T_{inst}$). This pulls the cone into the expansion clip, locking it against the concrete.

Mechanical vs. Chemical (Injection) Anchors

Fischer also produces "Chemical Anchors" (like the FIS V or FIS EM Plus resins).

• Mechanical Bolts: Provide immediate load capacity and are faster to install.

• Chemical Anchors: Are better for close-to-edge applications because they don't exert expansion pressure that might crack the concrete edge. They are also superior for underwater or vibration-heavy machinery mounts.