Thank you for raising this—rusty bolts after one year usually point to hardware selection or coating quality, not bad luck. In our outdoor bench factory, exposed fasteners are treated as a corrosion-control system, not a last-minute add-on.

As standard, we use A2-70 (304) stainless steel bolts for exposed joints on general outdoor benches. For coastal projects, chlorinated pools, de-icing salt zones, or high-humidity sites, we recommend and supply A4-70 (316) stainless steel. We avoid 201 stainless and ordinary zinc-plated carbon steel bolts on exposed outdoor connections because they can corrode quickly in wet or salty conditions.

Where stainless is not required, we use hot-dip galvanized steel hardware to ISO 1461 or an equivalent standard, with zinc-nickel or Dacromet coatings available for specific designs. We also control the details that cause early rust: matching hardware to the frame material, using nylon or EPDM isolation washers between dissimilar metals, applying anti-seize lubricant to stainless threads, and passivating stainless parts after machining.

Before shipment, hardware samples are checked for coating thickness, thread fit, and salt-spray performance according to the project specification. We can also provide material certificates and finish reports. If you share your climate, frame material, and expected service life, we will recommend the right hardware package—304, 316, hot-dip galvanized, or a mixed solution—so your next bench order does not repeat the one-year rust problem.