HOLO-KROME 650000392 1/4-28 x 1/4" 內六角螺絲 | 圓頭內六角驅動 | 合金鋼熱處理黑色氧化 (25顆/包)

Came in a neat 25-pack, and the thermal black oxide finish is even and doesn’t flake off when I torque them into aluminum. Threads started clean with a driver, no cross-threading fuss. Only wish the package had a few spares for when I drop one behind the bench.

I needed a handful of these for a jig I was building, and the 1/4-28 thread cut cleanly without any binding. The button head sits nicely flush, which was exactly what I wanted for that tight spot.

The black oxide finish on these screws looks great and resists wear well. I used them to secure a precision bracket, and they threaded smoothly without any binding. Exactly what I needed for my current project.