5/16-24 X 1-1/4" 內六角螺絲 | 六角驅動 | 尼龍防鬆膠 | 全牙 | 合金鋼 熱處理黑氧化物 (100個/包)

Used a handful of these in a jig I’m building and the thermal black oxide finish has held up nicely without any chips or rust so far. The hex socket drive seats cleanly with a standard Allen key, and the nylon patch keeps them snug even under vibration.

The nylon patch on these is a lifesaver—they held tight on my milling machine fixture even after a full shift of vibration. The black oxide finish looks clean and hasn't shown a speck of rust in the week I've had them in the shop.

Used these to repair the indexing fixture on my mill, and the thermal black oxide finish seems tougher than the standard black oxide I’ve tried before. The hex socket drive seated perfectly with a 3/16" Allen key, no stripped heads.