5/16-18 x 8" 馬車螺栓 | A307 等級A 鍍鋅鋼 (50 顆/包)

The square neck grabbed into the wood instantly—no spinning or wrenches needed to hold it steady while I tightened the nut. Zinc plating looks clean and even across all fifty, and they’ve held up fine in the damp garage so far.

I’ve used a lot of carriage bolts over the years and these are the first ones where the zinc plating actually stayed intact after being torqued down with a socket. The smooth rounded head sits flush enough that I didn’t have to grind anything down on my fence repair.

The square neck on these grabbed the wood instantly and held tight while I cranked the nut down, no spinning or swearing. The zinc coating looks clean and even across all 50 bolts.