HOLO-KROME 73108 3/8-24 X 1-1/4" 內六角螺絲 | 六角驅動 | 合金鋼 熱處理黑色氧化 (100 顆/包)

The black oxide finish on these is flawless, and the hex socket drive sits perfectly snug with no wobble. I’ve bought cheaper cap screws before, but these feel noticeably sturdier for the precision assembly work I’m doing.

I’ve been using these in a jig I’m building, and the black oxide finish makes them slide into place without any galling. The hex drive bites firmly with a standard Allen key, and all 100 came with clean, uniform threads.

Threads are consistently clean and the hex drive bites perfectly with my 3/8” Allen key, no stripping even on the first torque pass through a steel jig. The thermal black oxide gives them a nice uniform dark finish that resists light shop grime so far.