1-1/4-7 × 7" 重型六角頭螺絲 | 18/8不鏽鋼 | 部分螺紋（2個/包）

The 18/8 stainless threads cut clean and didn't gall at all, which surprised me for bolts this size. Used them to anchor a trailer hitch plate and the hex heads took a breaker bar without rounding.

These held up great bolting down a piece of shop equipment, and after a few weeks outside there's not a spot of rust on them. The 7" length gives you plenty of shank to work with, and the partial threading lets the unthreaded section sit flush through the plates.

The 18/8 stainless is a big step up from the zinc-plated hardware I kept replacing on my trailer. Seven inches of shank with the threads only on the lower half means the unthreaded section sits flush through the bracket instead of chewing it up.