مسامير نقل 5/16-18 × 3-1/2 بوصة | ملولبة بالكامل | فولاذ مقاوم للصدأ 316 (50 / عبوة)

I’ve been using these fully threaded 316 stainless bolts for a dock repair, and the square neck locks in tight without any spinning. The 5/16-18 size was a perfect fit for my pre-drilled holes, and the 3-1/2” length gave me enough thread to secure everything firmly.

The square neck on these bolts grabbed instantly when I tightened them, no spinning at all. I’ve used cheaper zinc-plated ones before that would strip, but these 316 stainless ones feel rock solid after a few days outside.

The 316 stainless steel has held up perfectly on my deck railing through two weeks of rain without a single rust spot. The square neck pulls in tight just like it should.