3/8-16 X 3-3/4" 套帽螺絲 | 平頭內六角驅動 | 部分螺紋 | 合金鋼熱處理黑氧化物 (50 個/包)

The threads are clean and the black oxide finish took a firm grip in my fixture plate without any galling. The partial threading gave me just the right amount of shank engagement for the alignment holes I was drilling. Solid feel for the price, and the hex socket seated true.

I used these for a custom jig build and the hex socket drive made installation a breeze even in tight spots. The thermal black oxide finish looks tough and seems like it’ll hold up well.

The flat head seats perfectly flush in my fixture, and the hex socket drive made tightening them in tight spots way easier than a standard bolt. Partial threading gave me just the grip I needed for a precision assembly, and the black oxide finish looks clean and professional.