There is no single universal hole-spacing standard for every outdoor bench, even when the bench comes directly from an outdoor bench factory. The correct spacing is determined by the bench frame, mounting plate, anchor type, substrate, and project requirements. That said, most factory-made outdoor benches follow a few common patterns. Along the length of the bench, mounting holes are typically spaced 18 inches (457 mm), 20 inches (508 mm), or 24 inches (610 mm) center-to-center. A 20-inch spacing is common on standard backless and park-style benches, while 24-inch spacing is often used on heavy-duty commercial benches. Some designs use 16 inches or 30 inches, and four-hole mounting plates may also have a front-to-back spacing that varies by leg design.

Hole diameter is usually 3/8 inch (10 mm) to 1/2 inch (13 mm), and some factories use slotted holes to allow minor alignment adjustments during installation. The most reliable answer to “What’s the standard hole spacing for mounting your benches from the outdoor bench factory?” is this: request the model-specific mounting template or CAD drawing from the factory. If the factory describes the spacing as “standard,” ask for the exact center-to-center dimensions in both directions, the hole diameter, the recommended anchor type, the minimum concrete thickness, and the required torque.

Always measure from hole center to hole center, not from edge to edge. Confirm the substrate before drilling: concrete, pavers, timber, and composite decks require different anchors and installation methods. For commercial projects, local code, ADA clearances, wind loads, security requirements, and drainage should govern the final placement. Use stainless or galvanized anchors in exposed outdoor locations, keep water from pooling around the feet, and verify level and stability after anchoring. If you need one practical starting point, 20 inches center-to-center is a common factory default for many outdoor benches, but it should never replace the factory drawing or project specification.