3/8-24 x 4" 內六角螺絲 | 平頭 內六角驅動 | 合金鋼 熱處理黑色氧化 (50個/包)

The flat head sits perfectly flush in my counterbores, and the black oxide finish was consistent across all fifty screws. These handled the torque for my press tooling without a single stripped drive.

I used these for a custom jig setup, and the hex socket drive made installation straightforward even in tight spaces. The 4-inch length was perfect for securing thicker material, and the black oxide finish has held up well without rust.

The black oxide finish on these screws is a nice touch—they slide into the hex driver without any stripping, even after a few hours of tightening down fixture plates. All fifty came out of the box with clean threads and no burrs.