Sidewalk Bolts
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
Sidewalk Bolts FAQs
See the accordion below for sizing, anchors, materials, and installation tips.
Disclaimer: This page provides general guidance. Always follow the product datasheet and the approved shutter system instructions.
A low-profile, wide-head machine screw used with anchors or nuts. The oversized head spreads load and sits nearly flush on panels.
They’re closely related. Sidewalk bolts typically have an even wider, flatter head than standard truss heads and are commonly specified for hurricane/shutter systems.
Programs often stock #10-24 and 1/4″-20 in multiple lengths. Choose the exact thread and length required by your shutter system or hardware.
For these low-profile heads, measure from under the head to the tip (flat heads that are truly countersunk are measured overall).
Use machine-screw anchors (female inserts) that match your sidewalk bolt’s thread. Install anchors according to the manufacturer’s drill-size and embedment instructions.
Flat or sealing (neoprene) washers are often used under the head to protect panel surfaces and help weather sealing, depending on the shutter system.
304 (18-8) suits most outdoor use. Choose 316 for coastal or chemically aggressive environments for improved corrosion resistance.
Zinc plating is best for dry interiors or short-term use. For long-term outdoor exposure, stainless is usually preferred.
Combo (slotted/Phillips) allows more tool options, which can help in field conditions. Use the drive specified by your system.
Tighten until the panel is secure and evenly clamped. Over-tightening can distort panels or damage anchors.
Use sidewalk bolts only as part of a shutter system that has the required local approvals. Follow the system’s hardware list and instructions.
Typically yes if threads and heads are undamaged and corrosion-free. Replace any that are bent, stripped, or excessively worn.
Stainless-to-stainless assemblies can gall. A small amount of compatible lubricant (if allowed by the system) and proper alignment helps reduce galling.