M42-4.5 X 360mm 內六角圓柱頭螺絲 | 內六角驅動 | 半牙 | 12.9級合金鋼熱處理黑氧化

Installed these 360mm screws on a jig table, and the hex socket drive handled a torque wrench without stripping. The black oxide finish also seems to resist shop grime better than I expected.

Used these for a heavy-duty press fixture and the 360mm length was exactly what I needed—the black oxide finish handled the shop grime without a single spot of rust after two weeks of use. Class 12.9 strength gives me real peace of mind on high-torque applications.

Installed these on a heavy jig I’m building and the hex socket drive made tightening them a breeze. The black oxide finish looks professional and seems resistant to oil and grime. Great fit for precision work where standard bolts won’t cut it.