M6-1 X 20mm 소켓 캡 나사 | 육각 드라이브 | 전체 나사산 | 클래스 12.9 합금강 열처리 블랙 옥사이드 (600/팩)

The black oxide finish holds up well on these even after tightening with a hex key, and the 12.9 grade gives me confidence they won't strip under torque. Used a handful for a jig build and they threaded smoothly into steel without any binding.

These screws have been perfect for building a custom jig, the hex socket drives cleanly without stripping. The consistent threading makes assembly quick and precise. Exactly what I needed for reliable machinery work.

The hex socket drive on these is a perfect fit for my jig assembly work, no stripping or wobble at all. Having 600 in one package means I can finally stop reordering mid-project.