The Simpson FSBIT Fascia Counterbore Bit from Simpson is a precision-engineered drilling accessory purpose-built for composite and PVC fascia installations. Constructed from Type 316 stainless steel, it bores a hole specifically sized so that, when the fascia screw is installed, the material can expand and contract as the environment changes - delivering a clean, professional result that prevents head pullover, broken screws, warping, buckling, and oil-canning. As part of the Simpson Strong-Tie Fascia-Fastening Solution, this counterbore bit works in tandem with Simpson Strong-Tie Fascia Board screws (sold separately) to form a complete, reliable fastening system for composite and PVC fascia boards.

Key Features

• Approved for Trex Fascia Board attachment - gives installers confidence that the bit meets manufacturer requirements for one of the most widely used composite fascia brands
• Crucial to proper fascia board installation - ensures the bore is sized correctly so the fascia material can move with thermal expansion and contraction, protecting the finished surface long-term
• Creates a clean pilot hole - reduces the risk of splitting, cracking, or surface damage during fastening for a professional-grade finish
• Countersinks the screw head flush with the material surface - eliminates raised fastener heads for a smooth, finished appearance on composite and PVC fascia
• 1/4 in. arbor fits standard drills - no specialty equipment required, so the bit integrates easily into a typical installer's existing tool setup
• Type 316 stainless steel construction - provides superior corrosion resistance, making the bit well-suited for exterior applications where moisture and harsh conditions are a factor

Why This Product

• Engineered specifically for composite and PVC fascia - unlike general-purpose bits, the FSBIT is designed around the unique demands of fascia board installations, where incorrect bore sizing leads to warping, buckling, and fastener failure
• Trex approved for fascia attachment - installers working with Trex fascia boards can use this bit with confidence, knowing it meets the approval standards required for a correct and warrantable installation
• Superior corrosion resistance for exterior use - Type 316 stainless steel construction means the bit holds up in outdoor environments where exposure to moisture, salt air, or the elements would degrade standard tool steel
• Part of a complete fascia-fastening system - the FSBIT pairs directly with Simpson Strong-Tie Fascia Board screws to deliver a matched, tested solution rather than a mix of unrelated components

Specifications

• Model Number: FSBIT
• Arbor Size: 1/4 in.
• Bore Diameter: 0.25 in.
• Counterbore Diameter: 0.41 in.
• Material: Type 316 Stainless Steel
• Finish: Type 316 Stainless Steel
• Country of Origin: United States

Approved Applications

• Composite fascia board installations
• PVC fascia board installations
• Approved for attachment of Trex Fascia Boards

Frequently Asked Questions

Why is the FSBIT counterbore bit necessary for fascia board installation?

Use of the fascia counterbore bit is crucial to proper installation of the fascia board. It bores a hole specifically sized to allow the fascia material to expand and contract as the environment changes, preventing issues such as head pullover, broken screws, warping, buckling, and oil-canning.

What drill is this bit compatible with?

The FSBIT features a 1/4 in. arbor, which fits standard drill bits and is compatible with most standard drills.

Does the FSBIT work with Trex Fascia Boards?

Yes. The FSBIT Fascia Counterbore Bit is approved for attachment of Trex Fascia Boards, making it a reliable choice for installations involving this brand of composite fascia material.

What screws should be used with the FSBIT Fascia Counterbore Bit?

The FSBIT is designed to be used with Simpson Strong-Tie Fascia Board screws, which are sold separately. Together, the counterbore bit and fascia screw form the complete Simpson Strong-Tie Fascia-Fastening Solution.

Note: Simpson Strong-Tie Fascia Board screws are sold separately and are required to complete the fascia-fastening system.