3/8-16 X 4 英吋六角頭螺絲 | 美國製造 | PFC9 合金鋼黃鋅 (50 入/包)

The hex heads didn’t strip even under a solid impact driver push, and that yellow zinc finish looks tough enough for outdoor wear. Threads cut clean into mild steel without any binding, so the whole package felt properly made. Fasteners are done right, plain and simple.

I needed some heavy-duty bolts for a press rebuild, and these 3/8-16 x 4" hex heads threaded in smoothly without any binding. The PFC9 alloy steel feels solid, and the head's hex drive made torquing them down easy with a wrench.

The yellow zinc finish wiped clean easily and the threads caught perfectly on the first try, no galling. These bolts feel rock-solid for the price, and the 50-count box is a nice bonus for a project that only needed a handful.