7/16-20 X 4" 內六角螺絲 | 六角驅動 | 部分螺紋 | 合金鋼熱處理黑氧化物 (50入)

Used these to mount a jig fixture on my mill table and the partial threading gave me just the right amount of grip without bottoming out. The hex socket drive made tightening them in tight spaces a breeze.

The black oxide finish on these screws held up perfectly during my jig build, no galling at all. They threaded cleanly into tapped holes and the hex socket drove true without stripping. Just the right grip for precision assemblies.

Finally, a socket screw that threads smoothly without binding halfway in. The black oxide finish is even and consistent all the way down the 4" length. Bolted up a jig plate today and these held tighter than the cheap ones I've used before.