#5-40 X 1/4" 內六角螺絲 | 內六角驅動 | 尼龍防鬆膠 | 全螺紋 | 合金鋼熱處理黑色氧化 (300/包)

I’ve been using these in a few jigs and a precision fixture, and the black oxide finish is holding up nicely without any rust after a week of shop use. The hex socket drive seated cleanly and the nylon patch gives just enough resistance to keep them snug.

The nylon patch on these screws locks them in place perfectly for precision assemblies, and the black oxide finish looks clean and professional. I used a full pack on a tooling jig without a single issue—they drive smoothly and hold tight.

Installing these in a jig fixture, the nylon patch held them snug without rattling loose during vibration testing. The hex socket drive made tightening consistent and easy with my T-handle.