Choosing the right fasteners is crucial for the longevity and safety of your wooden outdoor benches. The best options are those that resist corrosion and provide strong, lasting hold in wood exposed to the elements.
For most joinery, such as attaching legs to seats or backrests to frames, corrosion-resistant deck screws are the top choice. Look for screws labeled as hot-dipped galvanized, stainless steel (304 or 316 grade), or coated with a superior polymer. These materials fight off rust caused by rain and humidity. Coarse-thread screws offer superior grip in softwoods like pine or cedar.
For critical structural points where extreme shear strength is needed—like connecting major load-bearing beams—lag bolts (or lag screws) are superior. Always pre-drill a pilot hole to prevent the wood from splitting. Pair them with washers to distribute the load and use matching weather-resistant nuts and washers for through-bolts.
Don't overlook weatherproof wood glue for added rigidity in joints, or corner brackets made of galvanized steel for extra support underneath the bench. Avoid plain steel or black drywall screws, as they will rust quickly, staining the wood and failing prematurely.
Ultimately, the "best" fastener combines high tensile strength with maximum corrosion resistance. Investing in quality hardware like stainless steel or heavily galvanized screws and bolts ensures your bench remains sturdy and secure for many seasons to come.