What Are Sidewalk Bolts?
Sidewalk bolts—often called hurricane bolts—are low-profile machine screws with an extra-wide, flat head. The broad head spreads load and sits nearly flush, so it won’t snag shoes, fabric, or panels. They’re commonly paired with female machine-screw anchors in masonry or with tapped/through holes and a nut.
What Are Sidewalk Bolts Used For?
- Attaching storm/hurricane panels (plywood, metal, or fabric) to preinstalled anchors in concrete, block, or masonry.
- Sheet-metal and enclosure work where a very low-profile head is preferred.
- Architectural, sign, and fixture mounting that benefits from a wide bearing surface.
Benefits of a Sidewalk Bolt
- Ultra-low profile: reduces trip/snAG points and improves appearance on exposed surfaces.
- Wide bearing surface: the oversized head distributes clamping force on thin panels.
- Simple installation: driver-installed (slotted or combo drives are common) with standard hand or power tools.
Sizes, Threads & Head/Drive Options
Order by diameter × thread × length (e.g., #10-24 × 1″ or 1/4″-20 × 1-1/2″). Stock ranges vary by supplier; many programs carry select diameters (such as #10-24 and 1/4″-20) in multiple lengths. Heads are typically very wide and shallow; drives are usually slotted or slotted/Phillips combo. Length is generally measured from under the head to the tip.
Materials & Corrosion Resistance
- 18-8 / 304 Stainless Steel: reliable outdoor corrosion resistance for most environments.
- 316 Stainless Steel: recommended for coastal or highly corrosive settings (availability varies).
- Zinc-Plated Steel: economical choice for dry interior use and temporary installations.
Installation Basics
- Choose the anchor: For masonry, use a machine-screw anchor (female insert) sized to the bolt’s thread. For through-bolting, use a matching nut and washer.
- Prepare panels: Drill clearance holes to suit the sidewalk bolt diameter. Consider neoprene or sealing washers if weather sealing is required by the shutter system.
- Drive & tighten: Install with a suitable screwdriver/bit. Snug the panel; avoid over-torque that can distort thin panels or crack anchors.
- Service & storage: After seasonal use, remove panels; clean and lightly lubricate stainless threads as needed.
Important: Hurricane-protection systems must follow the manufacturer’s instructions and local code approvals.
Related Hardware
- Machine screw anchors (female masonry anchors)
- Flat, finish, or sealing (neoprene) washers
- Matching stainless nuts for through-bolted installations