7/16-14 X 1-1/8" 內六角圓柱頭螺絲 | 平頭內六角驅動 | 全牙 | 合金鋼熱處理黑色氧化 (100 / 包)

The thermal black oxide finish is the first thing I noticed pulling these out of the package, and it's a nice, even coating that hasn't chipped during assembly. Threads are clean and cut deep, and they seat perfectly in my jig fixtures with no binding. These will definitely be my go-to for precision

The hex socket drive makes installation so much easier than a regular hex key, and the black oxide finish has held up well on my jig builds. I used a full 30 of them for a tooling fixture without a single issue.

Put a dozen of these into a precision fixture I'm making, and the flat heads sit perfectly flush every time. The black oxide finish looks clean and seems durable so far.