HOLO-KROME 76200 M6-1 X 55mm 插座帽螺絲 | 六角插座驅動 | 合金鋼 熱處理黑色氧化物 (100個/包)

The black oxide finish on these is flawless—no chips or uneven spots across the whole pack. Threads seated cleanly into my steel fixture plates without any binding, and the hex socket drive grabbed perfectly every time. Exactly what I needed for a precision assembly.

Installed a full row of these in a jig plate for drilling fixtures—the hex socket drive made tightening them much easier than slotted screws. Threads were clean and consistent across the whole pack of 100. Only wish they came with a few extras in case one gets dropped.

Needed some strong M6s for a jig I’m building, and these 55mm screws are the perfect length. The black oxide finish looks solid and should resist corrosion well. They’re a bit tight to start threading, but once seated they hold firm.